Our family spends a great deal of time in the car. Like any neurotic mom, I find "car time" to be the perfect place to practice basic facts. I am always calling out capitals, math facts and spelling words. Our kids seem to love it and it adds some fun to the tedious task of learning these basics.
Last week, I had a rare moment alone with our Kindergartner. On our way to soccer practice he asked me to play a math game with him. Music to my ears! We began with basic addition and subtraction facts. After a few minutes, he asked me if we could learn something new. Again, music to my ears! So, I thought I would push the envelope, negative numbers. Here's how the conversation went:
Mom: Andrew, let's pretend we live in Barrow, Alaska. Okay?
Andrew: Ooooh, it's really cold up there! I'll need my fuzzy hat.
Mom: Yes, you will! I am so glad you brought up the weather. I want to ask you some questions regarding temperature. Let's pretend the temperature outside is four degrees Fahrenheit.
Andrew: That is so cold! I bet it's snowing. I wish it would snow here!
Mom: Me too! After the sun went down, though, the temperature dropped five degrees. What is the new temperature?
Andrew: Let's see. I start at four and go back five places. (Note: I teach addition and subtraction using a number line.) So, that would be three, two, one, zero. Zero! Is it zero?
Mom: Well, let's see. If we start at four and go back to zero that's only four places. Remember, the temperature dropped five degrees.
Andrew: Oh yeah, that's right. Well, three, two, one, zero, negative zero. No, no. You can't have a negative zero. Negative one. Mom, is it negative one?
Mom: Wow, very good! Yes, it is! How did you decide on the answer negative one?
Andrew: Well, it can't be zero. I knew it had to be below zero. So, I thought about negative one. Can we do another one? I like this negative weather math game!
Like any good mother we continued to do several more problems. Andrew was so excited and proud of himself! He knew he was doing "big boy math" and couldn't wait to share the good news with his older brother and sisters. As a math teacher, I was excited because a door has been opened.
As I worked through several weather examples with our five year old, I began to wonder why we wait so long to introduce the concept of negative numbers. Sure, he may not have an expert understanding, however, a foundation as been laid. During our conversation, he mentioned that he had heard of negative temperatures on television. When trying to solve the original problem, he was able to draw upon that prior knowledge and apply it to a new situation. Very exciting! As someone who works with many Pre Algebra and Algebra students, I know negative numbers can be a stumbling block causing hours of anguish. With our children, I have chosen to introduce the idea early fending off future fears. Hopefully, the forecast will be sunny and bright!
PS I am currently creating K-4 materials centered around our "negative weather math." I'll share when finished.