Creating and manipulating expressions and formulae

There are 198 NRICH Mathematical resources connected to Creating and manipulating expressions and formulae
Old Nuts
problem

Old Nuts

Age
16 to 18
Challenge level
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In turn 4 people throw away three nuts from a pile and hide a quarter of the remainder finally leaving a multiple of 4 nuts. How many nuts were at the start?
Absurdity Again
problem

Absurdity Again

Age
16 to 18
Challenge level
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What is the value of the integers a and b where sqrt(8-4sqrt3) = sqrt a - sqrt b?
Reaction rates!
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Reaction rates!

Fancy learning a bit more about rates of reaction, but don't know where to look? Come inside and find out more...
Magic squares for special occasions
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Magic squares for special occasions

This article explains how to make your own magic square to mark a special occasion with the special date of your choice on the top line.
Telescoping Functions
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Telescoping Functions

Take a complicated fraction with the product of five quartics top and bottom and reduce this to a whole number. This is a numerical example involving some clever algebra.
Price Match
problem

Price Match

Age
7 to 11
Challenge level
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Can you find pairs of differently sized windows that cost the same?
The Simple Life
problem

The Simple Life

Age
11 to 14
Challenge level
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The answer is $5x+8y$... What was the question?