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'X Is 5 Squares' printed from https://nrich.maths.org/

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Why do this problem?

This problem might be a challenge for younger learners but it allows them to use and think about some of the mathematical facts that they have learned. It is wonderful for paired or group work.

Key questions

What are the possible numbers to go into the middle square?
If you put that number there what numbers are left to use?

Possible extension

Learners could be encouraged to return to the problem and to check each of the conditions against their solution so that they can prove why their solution works.

Possible support

Many children will find it helpful to use a set of digit cards from $0$ to $9$ so that they can be moved around.