## Saturday, May 21, 2016

### Inverses

I love inverses but its kind of hard to teach them to students because they don't always understand precisely what inverse means.  So I'm always on the lookout for ideas to use when teaching the topic.

I came across this nice website with comics that operate as a hook for the topic. In addition, she offers ideas for introducing and teaching the topic so its a step by step process.  Her suggestions are quite clear and I like the examples she's used. She has it going from simple to more complex which is great.

I found this nice introduction on inverses that use map directions as a way of introducing inverses. The author gives the directions to a place and the student has to write the directions going from the place back to the origin.  I really like that the activity builds on prior knowledge.  Unfortunately, out in the village, they don't operate on blocks and streets.  Its more like ohhh the house with the new porch, or the one next to where the old chicken coop used to be.

The author then introduces inverses using a verbal number problem that requires the student to write it in the reverse way.  It then goes on to show how inverses appear in graph form.  Its done in a nice logical manner.

This site has a great partner share activity on inverse functions. The activity had pairs receiving one function and one inverse but not of the same original problem.  They had to find the student with the matching inverse for the function and function for the inverse.  This meant students had to know how to find the inverse and it generated discussion.  I wonder if I can extend this to include graphs to match the functions and inverses?

So now back the the blog Math Equals Love.  She creates units for interactive notebooks.  This one discusses domain, range, and at the very end, she includes inverse function notes. She looks at inverses from points, equation, and graph which is really nice. I know from personal experience the usual way the topic is covered is to only look at the equation.  Students do need all three.  This is a second way she covers the same material for inverses.

So once we know how to find inverses, how are they used in real life?  Stay tuned for tomorrow.