Math and Shopping

Sometimes, I can't believe just how much math that I use on a regular basis.  I use it at work, at school, and most importantly to me, at the store.  Since I'm a mom, I work, and I go to school, I'm constantly trying to stay on budget with my money.  A lot of times I use math without even thinking about it, as I imagine that many of us do.  When I'm in the grocery store, I use rounding, and compatible numbers.  I tend to round up to the nearest dollar, and then add the compatible numbers.  To find more on compatible numbers, go to:  http://www.northstarmath.com/sitemap/CompatibleNumber.html .

I suppose, that if I really thought about it, I use a lot of mathematical properties while shopping as well.  For example, when you go to the grocery store, and you are adding the milk, cheese, and bread together, you can do it in any sort of order and the price of all three stays the same, right? Milk+ cheese+ bread= bread+ cheese+ milk  Even if you add the milk and the cheese and and get a certain price, only to later remember the bread and then add it in, it is the same as if you added the cheese and the bread, and then remembered the milk and quickly added it into the total. (Milk+ cheese)+ bread= (cheese+ bread)+ milk  The first example is the Commutative Property for Addition, and the second example is the Associative Property and the Commutative Property together.

 Image:  rjdposters.com