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Six Is the Sum

What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?

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(w)holy Numbers

A church hymn book contains 700 hymns. The numbers of the hymns are displayed by combining special small single-digit boards. What is the minimum number of small boards that is needed?

Spell by Numbers

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

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.