lesson

Line up equal places

1 · Learn

In column addition, ones go under ones, tens under tens and hundreds under hundreds. Start by adding the ones.

If a column makes ten or more units, exchange ten of those units for one in the next column. Record the exchange so it is not forgotten.

247 + 135Ones: 7 + 5 = 12Tens: 4 + 3 + 1 = 8Hundreds: 2 + 1 = 3
Key words and supplied examples.

2 · Worked example

For 247 + 135, write 2 ones and carry 1 ten. Eight tens and three hundreds give 382.

3 · Your turn

Use columns to calculate 368 + 254. Explain both exchanges.

Check your answer

622. Twelve ones become 2 ones and 1 ten. Twelve tens become 2 tens and 1 hundred. The hundreds total 6.

4 · Apply your learning

Check the result with expanded place values and compare it with an estimate of about 600.

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Use objects or a drawn model before relying on a rule. Explain each step, check the units and revisit with varied examples. An adult can read the instructions without supplying the answer.

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