Number 19 & 20 are a little tricky. But think: as you move to the left, the place value each time increases by 10 (or multiply by 10 - x10). So, as you move to the right, the place value each time decreases by 10 (or divides by 10 - /10). So, how could you explain the difference in place value? Use the tool or tool to write on the task cards.