List

Trial and Improvement

Fifteen cards
problem
Favourite

Fifteen cards

Age
7 to 11
Challenge level
filled star empty star empty star
Can you use the information to find out which cards I have used?
Four-digit targets
problem
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Four-digit targets

Age
7 to 11
Challenge level
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You have two sets of the digits 0-9. Can you arrange these in the five boxes to make four-digit numbers as close to the target numbers as possible?
Factor-Multiple Chains
problem
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Factor-Multiple Chains

Age
7 to 11
Challenge level
filled star filled star empty star
Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?