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Multiples Sudoku
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Multiples Sudoku

11 to 14
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Each clue in this Sudoku is the product of the two numbers in adjacent cells.

Grandma's Cake
problem

Grandma's Cake

11 to 14
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What is the smallest number of pieces grandma should cut her cake into to guarantee each grandchild gets the same amount of cake and none is left over?
Semicircular Design
problem

Semicircular Design

14 to 16
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Weekly Problem 9 - 2016
The diagram to the right shows a logo made from semi-circular arcs. What fraction of the logo is shaded?
Number Spirals
problem

Number Spirals

7 to 11
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This task opens up an investigation of a different kind of spiral. This may open doors to new ideas.
Months and Years
problem

Months and Years

14 to 16
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The product of Mary's age at her last birthday and her age in complete months is 1800. How old is Mary?
True or False?
problem

True or False?

7 to 11
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Without doing lots of calculations, can you decide which of these number sentences are true? How do you know?
Endorsement
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Endorsement

Find out where NRICH has been recommended.

ABC
problem

ABC

7 to 11
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In the multiplication calculation, some of the digits have been replaced by letters and others by asterisks. Can you reconstruct the original multiplication?

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