Fractions

There are 129 NRICH Mathematical resources connected to Fractions
Same Shapes
problem

Same Shapes

Age
5 to 7
Challenge level
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How can these shapes be cut in half to make two shapes the same shape and size? Can you find more than one way to do it?
Doughnut
problem

Doughnut

Age
7 to 11
Challenge level
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How can you cut a doughnut into 8 equal pieces with only three cuts of a knife?
Racing odds
problem

Racing odds

Age
11 to 14
Challenge level
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In a race the odds are: 2 to 1 against the rhinoceros winning and 3 to 2 against the hippopotamus winning. What are the odds against the elephant winning if the race is fair?
Archimedes and numerical roots
problem

Archimedes and numerical roots

Age
14 to 16
Challenge level
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The problem is how did Archimedes calculate the lengths of the sides of the polygons which needed him to be able to calculate square roots?
Unit fractions
problem

Unit fractions

Age
11 to 14
Challenge level
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Consider the equation 1/a + 1/b + 1/c = 1 where a, b and c are natural numbers and 0 < a < b < c. Prove that there is only one set of values which satisfy this equation.
Bull's Eye
problem

Bull's Eye

Age
11 to 14
Challenge level
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What fractions of the largest circle are the two shaded regions?
3388
problem

3388

Age
11 to 14
Challenge level
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Using some or all of the operations of addition, subtraction, multiplication and division and using the digits 3, 3, 8 and 8 each once and only once make an expression equal to 24.
Look before you leap
problem

Look before you leap

Age
16 to 18
Challenge level
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Relate these algebraic expressions to geometrical diagrams.
Plutarch's Boxes
problem

Plutarch's Boxes

Age
11 to 14
Challenge level
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According to Plutarch, the Greeks found all the rectangles with integer sides, whose areas are equal to their perimeters. Can you find them? What rectangular boxes, with integer sides, have their surface areas equal to their volumes?