Odd and even numbers

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Favourite

Odds and Evens

Age

11 to 14

Challenge level

Are these games fair? How can you tell?
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Favourite

Odds, Evens and More Evens

Age

11 to 14

Challenge level

Alison, Bernard and Charlie have been exploring sequences of odd and even numbers, which raise some intriguing questions...
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Favourite

Magic Letters

Age

11 to 14

Challenge level

Charlie has made a Magic V. Can you use his example to make some more? And how about Magic Ls, Ns and Ws?
problem

Score

Age

11 to 14

Challenge level

There are exactly 3 ways to add 4 odd numbers to get 10. Find all the ways of adding 8 odd numbers to get 20. To be sure of getting all the solutions you will need to be systematic. What about a total of 15 with 6 odd numbers?
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Comparing Continued Fractions

Age

16 to 18

Challenge level

Which of these continued fractions is bigger and why?
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Next-Door Numbers

Age

5 to 7

Challenge level

Florence, Ethan and Alma have each added together two 'next-door' numbers. What is the same about their answers?
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The Set of Numbers

Age

5 to 7

Challenge level

Can you place the numbers from 1 to 10 in the grid?
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Sorting Numbers

Age

5 to 7

Challenge level

Can you sort numbers into sets? Can you give each set a name?
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What Number?

Age

5 to 7

Challenge level

I am less than 25. My ones digit is twice my tens digit. My digits add up to an even number.
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Numbers as Shapes

Age

5 to 7

Challenge level

Use cubes to continue making the numbers from 7 to 20. Are they sticks, rectangles or squares?