Reasoning, convincing and proving

There are 458 NRICH Mathematical resources connected to Reasoning, convincing and proving
Olympic Measures
problem

Olympic Measures

Age
11 to 14
Challenge level
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These Olympic quantities have been jumbled up! Can you put them back together again?
Nutrition and Cycling
problem

Nutrition and Cycling

Age
14 to 16
Challenge level
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Andy wants to cycle from Land's End to John o'Groats. Will he be able to eat enough to keep him going?
Factorising with Multilink
problem

Factorising with Multilink

Age
14 to 16
Challenge level
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Can you find out what is special about the dimensions of rectangles you can make with squares, sticks and units?
Always a multiple?
problem

Always a multiple?

Age
11 to 14
Challenge level
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Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...
Double Trouble
problem

Double Trouble

Age
14 to 16
Challenge level
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Simple additions can lead to intriguing results...
Walking round a triangle
problem

Walking round a triangle

Age
5 to 7
Challenge level
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This ladybird is taking a walk round a triangle. Can you see how much he has turned when he gets back to where he started?
Square subtraction
problem

Square subtraction

Age
7 to 11
Challenge level
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Look at what happens when you take a number, square it and subtract your answer. What kind of number do you get? Can you prove it?
Take three numbers
problem

Take three numbers

Age
7 to 11
Challenge level
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What happens when you add three numbers together? Will your answer be odd or even? How do you know?
Odd times Even
problem

Odd times Even

Age
5 to 7
Challenge level
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This problem looks at how one example of your choice can show something about the general structure of multiplication.
Two numbers under the microscope
problem

Two numbers under the microscope

Age
5 to 7
Challenge level
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This investigates one particular property of number by looking closely at an example of adding two odd numbers together.