Factors and multiples
problem
Favourite
What numbers can we make now?
Age
11 to 14
Challenge level
Imagine we have four bags containing numbers from a sequence. What numbers can we make now?
page
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
Favourite
5 by 5 Mathdokus
Age
7 to 16
Challenge level
Can you use the clues to complete these 5 by 5 Mathematical Sudokus?
problem
Favourite
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?
game
Celebrate 25 Years of NRICH
To celebrate NRICH's 25th birthday, why not play this special version of our classic game, Got It? Can you devise a strategy so that you will always win?
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
What does it all add up to?
Age
11 to 18
Challenge level
If you take four consecutive numbers and add them together, the answer will always be even. What else do you notice?