lesson
Explain what each calculation finds
1 · Learn
A multi-step problem needs a sequence of meaningful operations. First identify the starting quantity, additions and removals. Column methods require matching place values; exchanging changes the partition of a value, not its total.
Use an estimate to check size and an inverse calculation to check arithmetic. Neither check alone guarantees that you chose the right operation for the story.
2 · Worked example
A collection has 28,675 cards, receives 4,890 and gives away 7,456. After receiving: 33,565. After giving away: 26,109. Adding 7,456 back gives 33,565.
3 · Your turn
A library has 42,380 books, receives 3,725 and removes 2,468. How many remain?
Check your answer
46,105 - 2,468 = 43,637 books.
4 · Apply your learning
Write the meaning beside each line of your working, then change the story so a different operation is needed.
Adult guidance and safety
Ask the learner to explain the method and check it using a different representation. Supply place-value grids, fraction strips, accurate diagrams and measuring tools where needed. These examples need varied practice; a short correct answer alone does not establish fluency.
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Check a calculation · Year 5 onward
Use this only when your teacher or adult allows a calculator for the task. Show your thinking first. It does not replace mental or written arithmetic and does not mark your lesson answer.
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