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Multiples Grid

Age 7 to 11
Challenge Level

Lulu and Sophie from St. Nicolas C. of E. Junior School, Newbury have sent us a solution to the Multiples Grid problem. Thank you both! For the first large square, they say:


The blue numbers are all multiples of 7.
The pink numbers are all multiples of 5.
The maroon numbers are multiples of 5 and 7. (Both.)

In this square:

they say:

The pink numbers are multiples of 2.
The blue numbers are multiples of 5 or 7.

Are you sure the blue could be multiples of 5? In this square:

they say:

The blue numbers are multiples of 11.
The pink numbers are supposed to be multiples of 8.
The maroons are multiples of 8 and 11.

In the next square:

they explain:

The blues are multiples of 9.
The pinks are multiples of 6.
The maroon numbers are multiples of 9 and 6.

Finally, in this last square:

Sophie and Lulu wrote:

The blues are multiples of 9.
The pinks are multiples of 4 or 8.

Thank you for sending us your solution, girls. Well done!


The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.
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