Reasoning, convincing and proving

There are 514 NRICH Mathematical resources connected to Reasoning, convincing and proving
More Number Pyramids
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More number pyramids

Age
11 to 14
Challenge level
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When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...

Multiplication square
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Multiplication square

Age
14 to 16
Challenge level
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Pick a square within a multiplication square and add the numbers on each diagonal. What do you notice?
Domino Sorting
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Domino sorting

Age
5 to 7
Challenge level
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Try grouping the dominoes in the ways described. Are there any left over each time? Can you explain why?
Consecutive negative numbers
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Consecutive negative numbers

Age
11 to 14
Challenge level
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Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?
Times Tables Shifts
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Times tables shifts

Age
7 to 11
Challenge level
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In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?

missing multipliers
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Missing multipliers

Age
7 to 14
Challenge level
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What is the smallest number of answers you need to reveal in order to work out the missing headers?
Noah
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Noah

Age
5 to 7
Challenge level
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Noah saw 12 legs walk by into the Ark. How many creatures did he see?
Rule of Three
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Rule of three

Age
11 to 14
Challenge level
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If it takes four men one day to build a wall, how long does it take 60,000 men to build a similar wall?
Halving
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Halving

Age
5 to 7
Challenge level
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These pictures show squares split into halves. Can you find other ways?

Break it up!
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Break it up!

Age
5 to 11
Challenge level
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In how many different ways can you break up a stick of seven interlocking cubes? Now try with a stick of eight cubes and a stick of six cubes. What do you notice?