Fractions

There are 129 NRICH Mathematical resources connected to Fractions
Pythagoras’ Comma
problem

Pythagoras’ Comma

Age
14 to 16
Challenge level
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Using an understanding that 1:2 and 2:3 were good ratios, start with a length and keep reducing it to 2/3 of itself. Each time that took the length under 1/2 they doubled it to get back within range.
Six Notes all Nice Ratios
problem

Six Notes all Nice Ratios

Age
14 to 16
Challenge level
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The Pythagoreans noticed that nice simple ratios of string length made nice sounds together.
Fractions jigsaw
problem

Fractions jigsaw

Age
11 to 14
Challenge level
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A jigsaw where pieces only go together if the fractions are equivalent.
How long is the Cantor Set?
problem

How long is the Cantor Set?

Age
11 to 14
Challenge level
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Take a line segment of length 1. Remove the middle third. Remove the middle thirds of what you have left. Repeat infinitely many times, and you have the Cantor Set. Can you find its length?
The Cantor Set
problem

The Cantor Set

Age
11 to 14
Challenge level
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Take a line segment of length 1. Remove the middle third. Remove the middle thirds of what you have left. Repeat infinitely many times, and you have the Cantor Set. Can you picture it?
Fraction Fascination
problem

Fraction Fascination

Age
7 to 11
Challenge level
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This problem challenges you to work out what fraction of the whole area of these pictures is taken up by various shapes.
Family Fortune
problem

Family Fortune

Age
11 to 14
Challenge level
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If three brothers will get £20 more if they do not share their money with their sister, how much money is there?
Couples
problem

Couples

Age
11 to 14
Challenge level
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In a certain community two thirds of the adult men are married to three quarters of the adult women. How many adults would there be in the smallest community of this type?
Once Upon a Time
problem

Once Upon a Time

Age
7 to 11
Challenge level
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Can you work out the height of Baby Bear's chair and whose bed is whose if all the things the three bears have are in the same proportions?
Harmonic Triangle
problem

Harmonic Triangle

Age
14 to 16
Challenge level
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Can you see how to build a harmonic triangle? Can you work out the next two rows?