Algorithms

There are 32 NRICH Mathematical resources connected to Algorithms
Probably a code?
problem
Favourite

Probably a code?

Age
16 to 18
Challenge level
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Is the regularity shown in this encoded message noise or structure?
Method in multiplying madness?
problem
Favourite

Method in multiplying madness?

Age
7 to 14
Challenge level
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Watch our videos of multiplication methods that you may not have met before. Can you make sense of them?
Skeleton
problem

Skeleton

Age
11 to 14
Challenge level
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Amazing as it may seem the three fives remaining in the following `skeleton' are sufficient to reconstruct the entire long division sum.

Sorted
problem

Sorted

Age
14 to 18
Challenge level
filled star empty star empty star
How can you quickly sort a suit of cards in order from Ace to King?
Placeholder: several colourful numbers
problem

A fine thing?

Age
16 to 18
Challenge level
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Second challenge cipher
Stage 5 Cipher Challenge
problem

Stage 5 cipher challenge

Age
16 to 18
Challenge level
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Can you crack these very difficult challenge ciphers? How might you systematise the cracking of unknown ciphers?
Placeholder: several colourful numbers
problem

Ip?

Age
16 to 18
Challenge level
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Seventh challenge cipher
Placeholder: several colourful numbers
problem

Up a semitone?

Age
16 to 18
Challenge level
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Fifth challenge cipher
Placeholder: several colourful numbers
problem

Semicircle

Age
16 to 18
Challenge level
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Fourth challenge cipher