How Do They Predict How Long People Live?

Today's topic came from thoughts of my father. He passed away a couple years ago, four months after my mother died. I know he missed her. Yesterday would have been is 100th birthday if he'd survived. I wondered how math was used to create actuarial tables used in insurance and other industries, so today we'll learn more about it.

Calculating how long a person will live involves some complex mathematical models that take into account various factors such as age, gender, health status, lifestyle choices, and genetic predispositions. While predicting an individual's lifespan with absolute certainty is impossible, actuarial science and life expectancy calculations provide valuable insights into average lifespans and mortality risks.

Actuarial tables are a fundamental tool used in life expectancy calculations. These tables are based on large sets of population data and provide statistical probabilities of survival and mortality at different ages. Actuaries use these tables to estimate life expectancies for different demographic groups and to calculate insurance premiums and pension benefits.

One of the key mathematical concepts in life expectancy calculations is the probability distribution function, which describes the likelihood of different outcomes. In the context of life expectancy, this function is used to model the distribution of ages at death within a population. By analyzing this distribution, actuaries can estimate the average lifespan and the probability of living to a certain age.

Another important mathematical concept is the concept of conditional probability. This concept is used to calculate the probability of an event occurring given that another event has already occurred. In the context of life expectancy, conditional probability is used to calculate the probability of surviving to a certain age given that a person has already reached a certain age.

Additionally, mathematical models such as the Gompertz law and the Lee-Carter model are used to analyze mortality trends and project future life expectancies. These models take into account factors such as historical mortality data, age-specific mortality rates, and cohort effects to make predictions about future mortality rates and life expectancies.

In conclusion, calculating how long a person will live involves complex mathematical models that take into account various factors such as age, gender, health status, lifestyle choices, and genetic predispositions. While these models cannot predict an individual's lifespan with certainty, they provide valuable insights into average lifespans and mortality risks, which are essential for insurance, pension planning, and public health policy. Let me know what you think about this, I'd love to hear. Have a great day.

Making Direct Instruction Better

No matter how you arrange your lesson, there is usually a span dedicated to direct instruction since direct instruction plays an important part in the math classroom. It helps students understand complex concepts, develops problem-solving skills, and builds a solid foundation for future learning. However, determining the best time for direct instruction can be challenging, as it depends on a variety of factors such as student age, attention span, and the complexity of the material. We'll look at some of those factors in a bit more detail.

First, one needs to look at the ability of students to pay attention. Younger students generally have shorter attention spans, so direct instruction sessions should be shorter and more focused. For elementary school students, direct instruction sessions of 10-15 minutes are often ideal, with frequent breaks or transitions to keep them engaged. In addition, many students who game may have shorter attention spans.

1. Then one needs to look at the complexity of the material being taught as it also influences the length of direct instruction. For more complex topics in classes such as advanced algebra or calculus, longer direct instruction sessions may be necessary to ensure students grasp the concepts fully. However, it is important to break down these longer sessions into smaller, more manageable segments to avoid overwhelming students.

   
   

   Furthermore, it is important to monitor student engagement since that is the key to effective direct instruction. Teachers should be mindful of the signs of student disengagement, such as fidgeting or inattentiveness, and adjust the length and pace of direct instruction accordingly. Interactive activities, hands-on learning experiences, and multimedia resources can also help maintain student engagement during direct instruction.

   
   

   Another area is the classroom environment as it can impact the effectiveness of direct instruction. A comfortable, well-organized classroom with minimal distractions can help students stay focused and engaged during direct instruction sessions.

   
   

   In addition, direct instruction should be followed by opportunities for students to practice, receive feedback and reflect on their learning. This can be done through group discussions, individual reflection exercises, or formative assessments.

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   In conclusion, the best time for direct instruction in the math classroom depends on a variety of factors, including student age, attention span, the complexity of the material, student engagement, and the classroom environment. By considering these factors and adjusting direct instruction accordingly, teachers can ensure that students receive the support and guidance they need to succeed in math. Let me know what you think, I'd love to hear. Have a great day.

Creating Guided Notes To Go With Videos Used In The Math Classroom.

Guided notes are an effective tool for enhancing student learning during video presentations in math class. These notes provide a structured format for students to follow along with the video, focus on key concepts, and actively engage with the material. Here’s how you can create guided notes to accompany videos shown in math class:

The first step is to identify any key concepts covered in the video before you begin creating guided notes. These concepts should align with your learning objectives and the content of the video.

Next, create an outline for the guided notes based on the key concepts. Organize the notes in a logical sequence that follows the flow of the video. Don't forget to include prompts and questions. So in addition to listing key concepts include prompts and questions that encourage students to think critically about the material. These can be fill-in-the-blank statements, multiple-choice questions, or short-answer questions.

Furthermore leave space for students to write their responses to the prompts and questions. This allows them to actively engage with the material and helps them organize their thoughts. Take this one step further and incorporate visual aids such as diagrams, graphs, or equations into the guided notes. These visual representations can help students better understand the concepts being presented in the video.

In addition, provide cues to turn a passive experience into an active one. When you include cues in the guided notes, they prompt students to pay attention to specific parts of the video. For example, you can instruct students to underline key terms or circle important information. Once the guided notes are created, review them to ensure that they are clear, concise, and aligned with the content of the video. Revise as needed to improve clarity and effectiveness.

1. The final step is to decide whether to distribute the guided notes before or after showing the video. Distributing them before can help students focus on key points during the video, while distributing them after can serve as a review and reinforcement of the material.

In conclusion, creating guided notes for videos shown in math class can enhance student learning by providing a structured framework for understanding key concepts, encouraging active engagement with the material, and facilitating comprehension and retention of the content.

Scaffolding Direct Instruction With Videos.

Videos can be powerful tools in the math classroom, especially when used to scaffold direct instruction. By carefully selecting and incorporating videos into your lessons, you can enhance student understanding, engagement, and retention of mathematical concepts. Here’s how you can effectively use videos to scaffold direct instruction in your math class:

First, choose relevant and engaging videos. Look for videos that directly align with the concepts you are teaching. The videos should be age-appropriate, clear, and engaging to maintain student interest. Consider using a variety of video formats such as animations, real-world examples, and instructional videos.

Always preview the videos before you assign it. Ensure that the content is accurate, clear, and at an appropriate level for your students. Pay attention to the pacing, as videos should not be too fast or too slow for students to follow.

Take time to provide context by introducing the video, explaining its relevance to the lesson and how it connects to the concepts students are learning. This helps students understand why they are watching the video and what they should pay attention to.

Furthermore, use the videos as a pre-teaching tool. Videos can be used to introduce new concepts or as a review before a lesson. This can help students build background knowledge and prepare them for the upcoming instruction.

If you are playing it as part of the lesson, encourage active viewing by pausing the video at key points to ask questions or discuss concepts. This helps students process the information and clarify any misunderstandings. Always provide guided notes or worksheets to complete while watching the video. This keeps them focused and helps them actively engage with the content. Once the video is done, provide students with follow-up activities such as discussions, problem-solving tasks, or hands-on activities to reinforce the concepts learned.

In addition, assess student understanding.Use the video as a formative assessment tool by asking questions or giving quizzes to check for understanding. This helps you identify any misconceptions that need to be addressed.

By incorporating carefully selected videos into your math instruction, you can scaffold learning, enhance understanding, and make math more accessible and engaging for your students. Let me know what you think, I'd love to hear.

Gerrymandering And Ham Sandwich Theorem.

I saw an article on the topic of gerrymandering and the ham sandwich theorem and my mind went huh? So I had to read it to see how they relate. I love how math explains so much.

Gerrymandering, the practice of manipulating the boundaries of electoral districts to favor a certain political party, is a hotly debated topic in modern politics. There are court cases galore on this topic. While the concept of gerrymandering is rooted in political strategy, its implications can be understood through the lens of mathematics, particularly the Ham Sandwich Theorem.

The Ham Sandwich Theorem, a fundamental principle in geometric measure theory, states that given any three objects in n-dimensional space (such as three shapes in a plane or three volumes in three-dimensional space), it is possible to divide them equally with a single cut, much like slicing a ham sandwich into two equal halves with a single slice. This theorem has interesting implications when applied to the concept of gerrymandering.

In the context of gerrymandering, imagine the objects as representing different groups of voters, and the cut as representing the boundary lines of electoral districts. The Ham Sandwich Theorem suggests that it is theoretically possible to draw district boundaries in such a way that the political influence of each group is evenly balanced, ensuring fair representation for all.

However, the practical application of the Ham Sandwich Theorem to gerrymandering is challenging due to the complexity of real-world political boundaries and the need to consider various factors such as population distribution, community interests, and legal requirements. In practice, gerrymandering often involves intricate boundary-drawing techniques that aim to maximize the political advantage of one party over another, rather than achieving true equality in representation.

Despite its limitations in addressing gerrymandering directly, the Ham Sandwich Theorem serves as a reminder of the importance of fairness and equality in the design of electoral systems. By understanding the mathematical principles behind gerrymandering, we can better appreciate the need for transparent and equitable practices in redistricting and electoral reform. Let me know what you think.

The Importance Of Bell Ringers And Exit Tickets

In the world of teaching mathematics, bell ringers (or warm-ups) and exit tickets still serve as invaluable tools for improving student learning and engagement in the classroom. These brief activities, typically done at the beginning and end of a class session, offer numerous benefits that contribute to a more effective learning environment.

First of all, bell ringers set the tone for the math lesson by activating students' prior knowledge and priming their minds for learning. By presenting students with a thought-provoking problem or question related to the day's topic, bell ringers stimulate curiosity and encourage students to mentally prepare for the upcoming lesson. This initial engagement helps capture students' attention from the outset, fostering a positive and focused learning atmosphere.

Next, bell ringers provide an opportunity for teachers to assess students' understanding of key concepts while identifying any misconceptions or gaps in their knowledge. By observing students' responses to the bell ringer activity, teachers can gauge the readiness of the class to work on the topic and tailor their instruction accordingly. This way, the teacher addresses any areas of misunderstanding or confusion before teaching the main lesson content. This aspect of bell ringers allows teachers to carry out formative assessment that allows teachers to differentiate instruction and provide targeted support to individual students as needed.

Similarly, exit tickets also serve as a valuable tool for assessing student learning and comprehension at the conclusion of a lesson. When a teacher poses a brief question or prompt related to the day's lesson objectives, it allows students to demonstrate their understanding and reflect on their learning experiences. This formative assessment feedback informs teachers so they can instructional decisions and helps them gauge the effectiveness of their teaching strategies, enabling them to adjust their approach as necessary to meet students' needs.

In addition to their assessment function, exit tickets also promote metacognitive awareness and reflective thinking among students. When prompting students to articulate what they have learned, what questions they still have, or how they plan to apply their learning, the exit tickets encourage students to engage in critical thinking and self-assessment. This reflective process not only reinforces learning but also fosters greater ownership and accountability for one's learning journey.

Overall, the strategic use of bell ringers and exit tickets in the math classroom enhances student engagement, assesses understanding, and promotes reflective thinking, providing teachers with ongoing assessment. Teachers who incorporate these brief yet powerful instructional strategies into their teaching practice, are able to cultivate a dynamic and supportive learning environment that empowers students to succeed in mathematics and beyond. Let me know what you think, I'd love to hear.

How Does Math Relate To Valentines Day?

Valentine's Day is often celebrated when people give flowers, chocolates, and heartfelt messages to others. Although this might not seem like a holiday closely associated with mathematics, a world of mathematical concepts and principles lie beneath the surface of romantic gestures. These concepts and principles add depth and intrigue to the celebration of love.

Furthermore, the exchange of flowers on Valentine's Day provides another opportunity to explore mathematical concepts. Florists meticulously arrange bouquets as they consider factors such as color, size, and shape to create visually stunning arrangements. The Fibonacci sequence, a famous mathematical pattern found in nature, often serves as a guide for arranging flowers in a visually pleasing manner. The spiral patterns observed in flowers such as sunflowers and roses closely follow the Fibonacci sequence, reflecting mathematical beauty in nature's design.

In addition, gift-giving on Valentine's Day involves mathematical considerations, especially when it comes to budgeting. Individuals often set budgets for Valentine's Day gifts, balancing the desire to express affection with financial limitations. If individuals consider mathematical optimization techniques so they maximize the value of their gifts within their budgetary constraints while considering factors such as the preferences of their loved ones and the available options in the market.

Moreover, the celebration of Valentine's Day provides an opportunity to explore mathematical concepts related to symmetry and geometry. Heart-shaped chocolates, cards, and decorations abound on Valentine's Day, all reflecting the universal symbol of love and mathematicians study the properties of geometric shapes such as hearts, examining their symmetry, curvature, and mathematical representations.

In conclusion, Valentine's Day may be a holiday centered on love and romance, but mathematics plays a hidden yet significant role in its celebration. From probability and combinatorics to geometry and optimization, mathematical concepts add depth and complexity to the rituals and traditions associated with Valentine's Day, reminding us that love and mathematics are intertwined in unexpected ways. Let me know what you think, I'd love to hear. Have a great day.

Swarming Cicadas, Stock Traders, And Crowds.

Swarming cicadas, stock brokers, and the combined knowledge of a crowd might seem like disparate topics, but they all intersect in the fascinating realm of mathematics. These seemingly unrelated phenomena actually share underlying principles that mathematicians and scientists use to understand collective behavior, decision-making processes, and patterns in nature and society.

Cicadas, insects known for their synchronized emergence in large numbers at certain intervals, exhibit a behavior known as swarming. This phenomenon, observed in various species of cicadas, is driven by mathematical principles related to prime numbers and survival strategies. Cicadas have evolved to emerge in large numbers at prime number intervals, such as 13 or 17 years, which reduces the likelihood of predators setting their breeding cycles with the cicadas' appearance, thus increasing their chance of survival.

Similarly, in the world of finance, stock brokers and investors rely on mathematical models and the combined knowledge of crowds to make informed decisions in the stock market. The wisdom of the crowd refers to the collective intelligence of a group of individuals, whose aggregated opinions or predictions tend to be more accurate than those of any single member. This concept is leveraged in various mathematical models, such as the efficient market hypothesis and the random walk theory, which posit that stock prices reflect all available information and follow a random pattern.

In addition, the mathematical principles underpinning swarming behavior and the wisdom of the crowd have applications beyond cicadas and stock markets. They are also relevant in fields such as artificial intelligence, where algorithms are designed to mimic the collective behavior of swarms or crowds to solve complex problems, and in decision-making processes in business, politics, and social sciences.

In essence, the study of swarming cicadas, stock brokers, and the wisdom of the crowd exemplifies the interdisciplinary nature of mathematics and its relevance in understanding complex phenomena in nature, society, and beyond. By applying mathematical principles to analyze patterns, behaviors, and interactions, researchers can uncover hidden insights and develop strategies to address real-world challenges, from predicting cicada emergences to navigating financial markets and harnessing collective intelligence for problem-solving. Let me know what you think, I'd love to hear. Have a great day.

How Short Can A Mobius Strip Be?

The Möbius strip is a fascinating mathematical concept that continues to captivate minds with its seemingly impossible and paradoxical nature. One of the intriguing questions that arise from playing with a Möbius strip is just how short can one be? Today, we'll explore that question and learn more about this topic since many teachers have had students create one in class.

Let's start with a bit of background. The Möbius strip, named after the German mathematician August Ferdinand Möbius, the person who discovered it in 1858. It is a non-orientable surface with only one side and one boundary. This odd creation is formed by taking a strip of paper, giving it a half twist, and then connecting the ends. The result is a single-sided, continuous loop that challenges conventional notions of geometry. 

The Möbius strip's most remarkable property is that it has only one edge and one surface. If you trace your finger along the surface, you would find yourself on both sides without ever lifting your finger. This inh built paradoxical nature makes the Möbius strip a favorite subject for mathematical explorations and artistic creations.

The question of how short this creation could be snagged the imagination of Richard Evan Swartz. He explored the topic using a computer program but due to a mistake in the program, he almost missed finding the answer. However, he kept playing with Möbius strips and that lead him to the answer.

1. The usual method of constructing a Möbius strip involves taking a rectangular strip of paper, twisting one end by 180 degrees, and then connecting the ends. The resulting Möbius strip has a length twice that of the original strip. Experience showed that a long thin strip is easier to make than a short, fat one. 

Back in 1977, several mathematicians theorized that a triangular shaped Möbius strip is as small as the strip can get but no one could prove it . They said the ratio between the length and width would be more than about 1.57 times or pi/2. It took another 50 years before someone one was able to come up with proof.

In order to address this question Swartz focused on the properties of a Möbius strip. At every point, there is a direction that a line travels edge to edge with no curvature. It is completely flat. Swartz recognized that there are places where the two lines cross forming 90 degree angles forming an T shaped intersection.

Swartz used these contortions to find a new length to width ration of 1.69. He moved on to other projects but still thought about this. One day, he realized that he'd made a basic error when he cut open a Möbius strip, realizing it was trapezoidal rather than a parallelogram. This lead to the understanding that he'd made a basic error in the computer program he'd been using to explore the topic.

This small change in understanding lead to the discovery that the ratio is the sqrt 3 or about 1.73 length times its width. In addition, the strip is so short, it ends up flattening into an equilateral triangle. Let me know what you think, I'd love to hear. Have a great day.

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Looking At Math Based Riddles

Mathematics often brings up images of complex equations and rigorous problem-solving, but hidden in the world of numbers lies the engaging world of math riddles. These brain-teasers not only offer a break from traditional learning but also provide an entertaining way to sharpen mathematical skills. In this article, we'll delve into the charm of math riddles and explore a few mind-bending examples to tickle your brain.

Math riddles combine the fun of jokes with numbers. They challenge our problem-solving abilities, encourage creative thinking, and add an element of playfulness to mathematical concepts. Whether you're a teacher looking for a fun way to reinforce lessons or looking a mental workout, math riddles offer an accessible and enjoyable solution.

Let's look a classic math riddle:

I am taken from a mine, and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

Answer: A pencil lead.

This riddle cleverly disguises a common item, highlighting the ability of math riddles to weave everyday objects into enigmatic puzzles.

Here is another one referred to as the Farmers Challenge.

Imagine you are a farmer with a sack of grain, a chicken, and a fox. You need to transport them across a river using a small boat, but the boat can only carry you and one other item at a time. The catch: if you leave the fox alone with the chicken, the fox will eat it; if you leave the chicken alone with the grain, the chicken will eat it. How do you get all three across the river safely?

Answer: Take the fox across first, then go back and take the chicken across. Leave the fox on the other side and take the grain across. Finally, go back alone to get the fox. No harm done!

Then there is the Missing Dollar riddle -

1. Three people check into a hotel room that costs $30. They each contribute $10, handing $30 to the hotel clerk. Later, the hotel clerk realizes there was a mistake, and the room should only cost $25. The clerk gives $5 to the bellboy and asks him to return it to the guests. On his way to the guests' room, the bellboy decides to keep $2 for himself and gives $1 back to each guest. Now, each guest has paid $9 (a total of $27), and the bellboy has kept $2, making a total of $29. What happened to the missing dollar?

Answer: There is no missing dollar. The $27 paid by the guests includes the $2 kept by the bellboy. The guests paid $25 for the room, and the bellboy kept $2.

Check out the Age Puzzle.

A puzzle to exercise your math and deductive reasoning:

A father is 3 times as old as his son. In 20 years, he will be just twice as old as his son. How old are they now?

Answer: Let the son's current age be x. The father's age is then 3x. In 20 years, the son's age will be x + 20, and the father's age will be 3x + 20. Since the father will be twice as old, the equation is 3x + 20 = 2(x + 20). Solving this, the son is currently 20 years old, and the father is 60.

We are finishing off with my favorite. St. Ives one

As I was going to St. Ives,

I met a man with seven wives,

Each wife had seven sacks,

Each sack had seven cats,

Each cat had seven kits:

Kits, cats, sacks, and wives,

How many were there going to St. Ives?

The answer is one.

Math riddles inject an element of fun into the world of numbers, making learning an enjoyable and interactive experience. These can be used to start or end a class. Puzzles such as these enhance problem-solving skills, promote creative thinking, and demonstrate that mathematics can be an exciting journey of discovery. So, have fun and think about building a library of math riddles to sprinkle through the year. Let me know what you think, I'd love to hear.

Make Instruction More Effective Part 2.

 

Last Friday, we started looking at ways that help students learn more in math class.  Today, we'll finish the suggestions since I didn't want to overload brains.  The last part of Friday's column was discussing ways to use mistakes in class to help improve student knowledge and we'll continue that today.

One important step is to have students slow down and really think about what they are doing. Create four incorrectly solved problems and place them around the room.  Have the students rotate around the room, stopping at each problem where they must discuss the error and write down using complete sentences, why the error occurred and how to correct it. As they rotate around the room, students are engaged in conversations on what other students have written and they write down whether they support the answers or if they disagree with the thoughts, they need to write down their evidence.

Furthermore, use math journals where students can record thoughts on concepts that they are having difficulty with,  They can talk about where they are getting tripped up, work the problem from start to finish, reflect on different strategies they used when they tried to solve it, or talk about other approaches they could have used.  This type of journaling helps synthesis learning while looking at unanswered questions.

We want students to develop methods of solving complex problems rather than just mimicking the teachers method. One way to nudge students in this direction, is to give students a thinking task and ask them to work in small random groups.  Thinking tasks are problem solving activities or mental puzzles designed to challenge thinking.  Have students stand while they work on these problems and do calculations, writing, etc on surfaces like white boards, blackboards, or windows where they can easily erase ideas that are not working out.  Teachers circulate but do not answer questions such as "Is this right?" so as not to stop their thinking processes.

The idea behind this is to encourage perseverance, collaboration, and explore their curiosity. Rather than assessing them on being right or wrong, assess them on their perseverance, collaboration, and thoughts on how to solve problems. Take it a step further by letting students know where they are and where they are going in their learning through the use of frequent checks, observations, and unmarked quizzes.  

Furthermore, summative assessments should focus less on answers and more on the process of learning.  Let me know what you think, I'd love to hear.  Have a great day.

Make Instruction More Effective Part 1.

 

At anytime of the year, we as teachers often need to adjust the testing routine, work on eliminating math anxiety, creating an environment that encourages mistakes, and develop critical thinking skills.  Although we often want to make changes in time for the new school year, changes can be made at the beginning of a semester, quarter, or after a break.

One of the big things teachers face are students who believe they cannot do math or are not born with the math gene.  One way to check their beliefs and help to change them is to ask students to write a math autobiography where they answer questions such as "How do you feel about math?" or "How did your relationship with math change overtime?" and then asking them to share answers with each other. Furthermore, it is best if teachers eliminate comments about something being easy because it can demotivate them and they are less likely to ask questions to clarify their understanding.

Next, think about engaging students as soon as they arrive in the classroom. To do this, have a warm-up, bell ringer, math riddles, or challenging brain teaser.  The brain teaser might be having students begin with a cross and then ask them to draw two more lines to intersect or cut the cross to form the most number of pieces.  On the other hand, a math riddle might be something like "You have two coins that equal 30 cents but one of the coins is not a nickel so what are the coins?". Both brain teasers and riddles require students to problem solve and think critically. 

Then think about ways that students can show what they learn in ways other than by taking a test especially as they are tested quite regularly though the school year.  Instead of testing, give frequent, short assessments that are made up of current and past topics so they have to retrieve information.  Give this type of assessment every two weeks just as a way of checking on students but they don't need to be graded. However, the teacher should note mistakes and change instruction accordingly.

If you do have to give tests, allow students to discuss material on the test before beginning it.  One way to keep them from starting the test is to have students place their pencils on the floor, and then spend about 5 minutes to talk about the problems they see.  

As far as mistakes go, it is best to let them make mistakes while giving them the opportunity to discuss mistakes with others can better place the information in their brains. Use mistakes as part of a class activity by dividing the class into small groups, then identify and reflect on common mistakes.  One does this by dividing the class into small groups, they are asked to generate a problem and solve it incorrectly. Next the groups rotate and they must identify the mistake made by the other group and solve the problem correctly.  Then students rotate again and they have to identify the mistake of the first group and how the second group corrected the problem.

In addition, try the which one is more right by presenting two incorrect problems - one conceptually incorrect and the other is incorrectly calculated - and ask students to determine which problem is more right.  By doing this activity, they have to think about nuances in problem solving.

I think this is enough for today.  Come Monday, I'll provide more suggestions.  Let me know what you think, I'd love to hear.