Subtraction by counting on
"Counting up is the friendly way to subtract," says Biscuit. "Take it slow."
1. Count on to find the difference. Follow the example.
a) 60 − 40 = b) 80 − 50 =
2. Take away.
a) 90 − 25 = b) 100 − 40 =
3. Bo had 80 gumnuts and gave away 30. How many left?
4. Check by adding: if 70 − 20 = 50, then 50 + 20 =