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Well done to everybody who had a go at this activity.

Kevin and Aurelius from Kingswood College School in Australia sent in this picture and explanation:

A We chose 4/4 because the numbers are the 2x table.

B We chose 2/3 because the top number 2 comes between 1 and 3 and 3 comes between 2 and 4.

C We chose 3 up the top because it comes between 2 and 4. We chose 5 down the bottom because it comes between 6 and 4.

D We chose 1 because all the top numbers are the same and chose 4 because the bottom numbers are the 2 x table.

E The top numbers are the 1x table going down so we chose 2. The bottom numbers are adding 1 each time.

F The top numbers are going down in 1s. The bottom numbers are going down in 1s.

G We chose 3 because it comes between the 4 and the 2. We chose 5 because it comes between 6 and 4. The numbers are going down in 1s.

H We chose 2 because the top numbers are going down in 1s and we chose 4 because it the bottom numbers are going down by 2s.

Well done to both of you for sending in these very clear explanations!

I wonder if there are any other possible solutions? If you've found anything different, please let us know by emailing us with your ideas.

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The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

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