Factors and multiples
problem
Favourite
What numbers can we make now?
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
Favourite
5 by 5 Mathdokus
Can you use the clues to complete these 5 by 5 Mathematical Sudokus?
problem
Favourite
4 by 4 Mathdokus
Can you use the clues to complete these 4 by 4 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
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?
If you take four consecutive numbers and add them together, the answer will always be even. What else do you notice?