Find the Missing Number

Match the cards in these games and see how many levels you can beat!
Missing Number Game #1
Missing Number Game #2

We have talked about the equals sign.  Many people think it means “the answer is”, but we are thinking of the equals sign as the middle of a balance.  Each side has to have the same value.

For example, 9 = 9.  We can see that both sides of the equals sign balance.  One side is not worth more than the other.  So, we can put the equals sign in different places, as long as each side balances.

3 = 2 + 1

7 + 2 = 9