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# Ring a Ring of Numbers

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Age 5 to 7

Challenge Level

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- Getting Started
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Thank you to everybody who sent in their ideas about this task. Harper from Bedfordshire shared what they noticed:

I found that if you put odd next to odd it makes an even difference. If you put even next to even it makes an even difference too. But if you put even next to odd you get an odd difference. So if you want an odd difference you have to put even, odd, even, odd. If you want an even difference you have to put all odd or all even.

Rukmini from Hopscotch Nursery noticed that there is a pattern in the sums of the pairs of numbers:

When the differences are all odd, the sums are all odd.

Well spotted! I wonder why the sums are all odd when the numbers are even, odd, even and odd?