Sales Tax And Scientific Method.

 

I was all set to write about one topic and I decided to discuss a different topic since it is one that only works in places where taxes are collected at checkout.  I am currently in Dubrovnik Croatia where I landed last night.  I've been out and done a bit of shopping since I tend to like to eat most of my food in my rented place.  

In the United States, tax is added on at the counter and it varies from jurisdiction to jurisdiction.  In some places in Alaska, it can be as low as 1/2 percent while in other places such as California, it can be over 10 percent.  Even within some states, the rates vary according to the county you are making your purchase in.  I know folks who carry a variety of sales tax cards so they are set for where ever they are.

Now, in all the places I've visited, the tax is included in the price of the item.  If the item says 5 Euros, that price has already had the taxes added in.  This is known as a Value Added Tax and it is usually a flat rate so you don't have to keep track of a variety of tax rates.  I know that in some countries like Canada or Iceland, if you keep the receipts and you've spent over a certain amount, you can get the tax refunded at the airport when you leave.  

The only thing I know of in the United States that has a value added tax is gasoline and diesel rather than adding in tax once you've paid for the gas. Of course, those taxes are road, federal, and some states that are added in but again, those are not the same everywhere so there is a large variation across the land while in most European countries, the price is consistent through the whole country. 

In addition, jurisdictions often have different rates of tax being charged depending on the items you are buying such as food.  In some places, they do not charge you for food that you buy but if you eat out in a restaurant, they do collect it.  In others, they have a different rate for regular things versus cars.  Sales tax can be quite confusing for many due to the different rules.

The thing I've wondered about is this - If you are operating using a value added tax, does it work out the same as if you add it later.  In other words if the country adds an 11 percent tax to the price so you pay the 11 percent on each item, does it work out the same as if you added up the cost of everything first before adding the tax?  This question might be a good one to pose if you'd like to teach students about formulating a hypothesis in math and then asking students for ways to test that question.

This is a nice class lesson to see which way the government might collect more funding.  Discuss the hypothesis with students, let them make a prediction, have them help create ways to test the hypothesis, do the experiment, and collect the answers. This activity shows how one can use scientific method in Math.  let me know what you think, I'd love to hear.