Dear Math Central,
Hello. My name is Alison, and I am 14 years old. I am currently an Algebra1 student in the eighth grade. Recently, we were given a project entitled "When Will I Ever Use This?" and asked to complete it with our assigned team. The report is broken down into four sections; each team member is assigned a certain part. I chose to complete Part 3, which is called "Ask An Expert." To complete this, I have to write an e-mail letter using the "Ask An Expert" homepage to find out about the expert's real life usage of my topic, in this case, integers. So, may I ask, how do you use integers in your everday life? Please write back as soon as possible. Thanks. Sincerely, Alison

Integers are so much a part of your everyday life that it is hard to imagine a situation where you don't use them.

I went on a trip this weekend and had to drive 600 kilometers. On part of the trip the speed limit was 100 kilometers per hour and on another stretch of road it was 110 kilometers per hour.

Yesterday when we went to lunch there were 5 of us but we only ordered 4 lunches since the fifth person was only 1 year old.

The city that we are visiting has street names that are integers. 1^st street South West, 2^nd street South West, ... 1^st avenue North West, 2^st avenue North West and so on. This made finding our hotel easy. The property of the integers that is really useful here is the fact that they are ordered. If I am driving along 3^rd avenue SW and have just crossed 5^th and 6^th streets NW then I know the next street is 7^th NW.

I use negative integers in my everyday life also, especially in the Winter. The temperature outside when I got up yesterday morning was -12^o C. The high for the day was -3^o C so the temperature rose -3 -(-12)) = 9 degrees Celcius.