Algorithms

problem
Skeleton

Age

11 to 14

Challenge level

Amazing as it may seem the three fives remaining in the following `skeleton' are sufficient to reconstruct the entire long division sum.
problem
Sorted

Age

14 to 18

Challenge level

How can you quickly sort a suit of cards in order from Ace to King?
problem
Probably a code?

Age

16 to 18

Challenge level

Is the regularity shown in this encoded message noise or structure?
problem
A fine thing?

Age

16 to 18

Challenge level

Second challenge cipher
problem
Jluuis or even Asutguus?

Age

16 to 18

Challenge level

Sixth challenge cipher
problem
Stage 5 cipher challenge

Age

16 to 18

Challenge level

Can you crack these very difficult challenge ciphers? How might you systematise the cracking of unknown ciphers?
problem
Ip?

Age

16 to 18

Challenge level

Seventh challenge cipher
problem
Up a semitone?

Age

16 to 18

Challenge level

Fifth challenge cipher
problem
Semicircle

Age

16 to 18

Challenge level

Fourth challenge cipher
problem
Vital?

Age

16 to 18

Challenge level

Third challenge cipher