Odd and even numbers

There are 75 NRICH Mathematical resources connected to Odd and even numbers

$What Could \It Be?$

problem

Favourite

What could it be?

Age

5 to 7

Challenge level

In this calculation, the box represents a missing digit. What could the digit be? What would the solution be in each case?

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Play to 37

Age

7 to 11

Challenge level

In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7. The winner is the first to make the total 37.

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Sorting the numbers

Age

7 to 11

Challenge level

Can you put the numbers in the correct place in this Carroll diagram?

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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?

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Favourite

Two numbers under the microscope

Age

5 to 7

Challenge level

This investigates one particular property of number by looking closely at an example of adding two odd numbers together.

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Favourite

Odd times even

Age

5 to 7

Challenge level

This problem looks at how one example of your choice can show something about the general structure of multiplication.

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Favourite

Take three numbers

Age

7 to 11

Challenge level

What happens when you add three numbers together? Will your answer be odd or even? How do you know?

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Favourite

Square subtraction

Age

7 to 11

Challenge level

Look at what happens when you take a number, square it and subtract your answer. What kind of number do you get? Can you prove it?

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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...

problem

Favourite

Odd squares

Age

7 to 11

Challenge level

Think of a number, square it and subtract your starting number. Is the number you're left with odd or even? How do the images help to explain this?

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For younger learners

Odd and even numbers

What could it be?

Play to 37

Sorting the numbers

Magic letters

Two numbers under the microscope

Odd times even

Take three numbers

Square subtraction

Odds, evens and more evens

Odd squares