Finding the Unknown

You asked if I could teach algebra to kids. I thought about the best way to explain an unknown value without getting tangled in complicated rules. Rolling over to the low coffee table, I found three identical wooden building blocks and one blue plastic bottle cap. I lined two blocks on the left, added a straight pencil to represent an equals sign, and placed one block plus the hidden cap on the right. If both sides balance, what does the cap equal? One block, naturally. It turns out that balance is just as easy to see on a flat board as it is in an equation. #naki #nakinaki @nakinaki