Addition and Subtraction Strategies: Clear Examples for Grades 1–3

When your child solves a sum, ask, “How did you work it out?” Their explanation can show you what they understand and what to model next.

The groups below are starting points, not fixed grade deadlines. Use objects and drawings, and stay with a strategy until it makes sense.

Start with small numbers

• Count on: for 8 + 3, start at 8 and count three more: 9, 10, 11.
• Count back: for 10 − 2, count two steps back: 9, 8. Show the two steps on a number line.
• Use a double: 6 + 7 is one more than 6 + 6, so it is 13.
• Make ten: split 5 into 2 and 3. Then 8 + 5 becomes 8 + 2 + 3 = 13.
• Connect the operations: if 3 + 5 = 8, then 8 − 5 = 3. Build the same three quantities to show why.

Work with tens and ones

For 34 + 25, combine 30 + 20 and 4 + 5. The total is 50 + 9 = 59.

On a number line, solve 47 + 26 by jumping 20 from 47 to 67, then 6 to 73. Split the second jump into 3 and 3 if landing on 70 helps.

For 52 − 48, think “How far from 48 to 52?” Count up 2 to 50 and 2 more to 52: the difference is 4.

Make a number friendlier

To solve 39 + 24, try 40 + 24 = 64, then remove the extra 1 you added: 63. Explain that final adjustment with objects or a drawing so it does not become a trick to memorize.

Extend to hundreds and regrouping

For 356 + 231, combine hundreds, tens and ones: 500 + 80 + 7 = 587.

For 42 − 17, show 42 as four tens and two ones. Exchange one ten for ten ones: now there are three tens and twelve ones. Remove one ten and seven ones to leave two tens and five ones, or 25.

Check whether an answer makes sense

Estimate 412 + 289 as about 400 + 300 = 700. An estimate helps check the exact answer, 701.

For practice pages and games, explore Addition & Subtraction Power-Up!. Pick one strategy, model a problem and invite your child to explain the next one.