Reasoning, convincing and proving

There are 514 NRICH Mathematical resources connected to Reasoning, convincing and proving
Guess What?
problem
Favourite

Guess what?

Age
7 to 11
Challenge level
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Can you find out which 3D shape your partner has chosen before they work out your shape?
Compare the Calculations
problem
Favourite

Compare the calculations

Age
7 to 11
Challenge level
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Can you put these four calculations into order of difficulty? How did you decide?
Fruity Pairs
problem
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Fruity pairs

Age
5 to 7
Challenge level
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Which two items of fruit could Kate and Sam choose? Can you order the prices from lowest to highest?

Less is More
problem
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Less is more

Age
7 to 11
Challenge level
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Use your knowledge of place value to try to win this game. How will you maximise your score?
Digit Addition
problem
Favourite

Digit addition

Age
5 to 11
Challenge level
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Try out this number trick. What happens with different starting numbers? What do you notice?

The Number Jumbler
problem
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The number jumbler

Age
7 to 14
Challenge level
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The Number Jumbler can always work out your chosen symbol. Can you work out how?
Fruity Totals
problem
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Fruity totals

Age
7 to 16
Challenge level
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In this interactivity each fruit has a hidden value. Can you deduce what each one is worth?

Triangle or No Triangle?
problem
Favourite

Triangle or no triangle?

Age
5 to 7
Challenge level
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Here is a selection of different shapes. Can you work out which ones are triangles, and why?

Name That Triangle!
problem
Favourite

Name that triangle!

Age
7 to 11
Challenge level
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Can you sketch triangles that fit in the cells in this grid? Which ones are impossible? How do you know?