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## 'Coloured Edges' printed from http://nrich.maths.org/

### Why do this
problem?

This problem
requires learners to work logically with numbers and shapes at the
same time. The best ways of finding a solution include using a
letter to represent the length of the side of the square.

### Key questions

What sort of number of tiles must you use to make a
square?

What sort of number of tile edges will make up the perimeter
of the square?

Have you thought of using a letter to represent the length of
the side of the square?

### Possible extension

Learners could try to arrange the tiles so that touching edges are
all the same colour. They could also try

Painting Cubes
which is a similar problem.

### Possible support

Suggest making a list of possible square numbers. Then using
squared paper and colouring the edges of the small squares within a
suitably sized larger square and finding the answer by trial and
improve.