Work with addition and subtraction equations.
Determine the unknown whole number in an addition or subtraction equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = _ – 3, 6 + 6 = _.
As I watched students work through their problem set, I noticed quite a few friends filling in the blanks like so: 5 = 2 – 3. Although I understood the mistake, I hoped that students could learn to read these statements with understanding. In response, I created a card game that I thought could help.
With all of the cards out on the table, I asked, which representation matches the number sentence? Good discussion ensued as students went to work pairing up the cards.
Here is an example of two cards that match: