Integer subtraction

I recently finished another video of mine, this time on the topic of subtraction of integers. You can watch it here:


Subtracting Integers


In it, I explain three different models that we can use to justify the rules for subtracting integers to the students. The three models are:

1) number line jumps;
2) concept of difference;
3) counters.

Please read about these models in more detail in my updated article How to teach operations with integers.

Comments

watchmath said…
In my opinion student will difficult to understand why when you subtract a negative number you should jump to to the rigth. They will just accept it as a rule.
8:19 PM, June 16, 2009
Maria Miller said…
The goal here IS to get students to accept these things as "rules" (such as the double negative thing), but also understand that they can be justified. Subtraction of a negative number can be worked out using these models - yet the models aren't the goal in themselves. They are just an "intermediary aid".
10:36 PM, June 16, 2009
Steve said…
It's a good way to teach the rule, but maybe a little dry. I try to make math fun for my kids - but I know it can't all be "dressed up".
6:16 PM, June 24, 2009
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