lesson
Choose useful mental steps
1 · Learn
Break a calculation into steps you can keep track of. For 348 + 7, add 2 to reach 350 and then the remaining 5.
For 562 − 30, remove three tens. Keep the hundreds and ones in mind. Mental calculation means choosing a clear method, not guessing quickly.
2 · Worked example
For 497 + 6, I add 3 to reach 500 and 3 more to reach 503.
3 · Your turn
Find 276 + 8, 438 − 20 and 351 + 200.
Check your answer
284, 418 and 551.
4 · Apply your learning
Explain each calculation aloud using place-value drawings or a number line if helpful.
Adult guidance and safety
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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