Grade 1 · Unit 1: Number and place value

Counting back

Take away by counting back.

Birds on a wire. If some fly away, fewer are left.

Flying away

12 birds sit on a wire. 3 fly away. How many are left? We subtract to find out.

Count back

Start at 12. Count back 3: 11, 10, 9. So 12 − 3 = 9.

Take away with a ten frame

Fill a ten frame with 10 counters. Take away 3. 7 are left, so 10 − 3 = 7.

Adding and subtracting are linked

If 9 + 3 = 12, then 12 − 3 = 9. Subtraction undoes addition. You can check a subtraction by adding.

What I learnt