Copyright © University of Cambridge. All rights reserved.

'Spell by Numbers' printed from https://nrich.maths.org/

Show menu

This was quite tricky but some of you made good solutions and told us how you worked them out.

Sarah from Tattingstone School said she started off with O because she could see that it left things unchanged. Here is her solution:

Sarah's solution.

Can you follow her description of what she did?

Here is another one from her friend Marion. She started with a different idea but still gets the solution. Is one way quicker than the other?

Marion's solution.