Addition and subtraction

problem
More less is more

Age

7 to 14

Challenge level

In each of these games, you will need a little bit of luck, and your knowledge of place value to develop a winning strategy.
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Mathdoku demonstration

This video of Charlie and Liz solving a 6 by 6 Mathdoku may give you ideas for strategies to try.
problem
6 by 6 Mathdokus

Age

7 to 16

Challenge level

Can you use the clues to complete these 6 by 6 Mathematical Sudokus?
problem
5 by 5 Mathdokus

Age

7 to 16

Challenge level

Can you use the clues to complete these 5 by 5 Mathematical Sudokus?
problem
4 by 4 Mathdokus

Age

7 to 14

Challenge level

Can you use the clues to complete these 4 by 4 Mathematical Sudokus?
problem
3 by 3 Mathdokus

Age

7 to 14

Challenge level

Can you use the clues to complete these 3 by 3 Mathematical Sudokus?
problem
Five more coins

Age

7 to 11

Challenge level

Could Ben have any amount of money between 5p and £2 in his pocket if he has five coins?
problem
Mathdoku

Age

7 to 11

Challenge level

Complete the Mathdoku grid using the clues. Can you convince us that the number you have chosen for each square has to be correct?
problem
Three neighbours

Age

7 to 14

Challenge level

Take three consecutive numbers and add them together. What do you notice?
problem
Napier's bones

Age

7 to 11

Challenge level

The Scot, John Napier, invented these strips about 400 years ago to help calculate multiplication and division. Can you work out how to use Napier's bones to find the answer to these multiplications?