Teaching article
Subtraction as taking away: show the starting amount
Show the initial collection, the removed part and the remaining part separately.
Before removing objects, record or describe the collection that is present. Children can then connect the amount removed and the amount remaining to that starting quantity, rather than seeing only an unexplained final pile.
Show the initial collection before taking anything away. The remaining amount needs to be interpreted in relation to that starting quantity.
Keep all three quantities in the conversation
- Build the starting collection.
- Move four tokens to the removal area.
- Count and label the remaining five.
Nine take away four leaves five: 9 − 4 = 5.
Keep removed objects visible without counting them as the remainder. Which group answers the subtraction question?
Use a clear boundary for removed objects.
Resources
- Maths Puzzle Generator — Choose arithmetic or missing-number questions only when they match the number relationship being explored.
Further reading
Read next
- Subtraction can compare two collections without taking any away
- Rotate an array and investigate what stays the same
- A fraction of a shape and a fraction of a set
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