I don’t really remember where the idea for this one came from. It is a representation of binary numbers.

We usually count using the decimal system. It is thought of as a system of counting in tens. It uses a 0 and nine other digits to represent all numbers. There is no specific symbol to represent ‘ten’. We have to use two columns of digits, for a 1 and a 0, to make 10. This system is sometimes called ‘Base 10’.

The headings of the columns can be written as:

10000s

1000s

100s

10s

1s

or

104

103

102

101

100

Binary is a system of counting in twos. It uses 0 and 1; there is no symbol for ‘two’. In a similar way to the decimal system, we have to use two columns of digits, for a 1 and a 0. This system is sometimes called ‘Base 2’. The column headings can be written as

16s

8s

4s

2s

1s

or

24

23

22

21

20

Similarly, Base 3 would use the digits 0, 1 and 2, but the equivalent of three would be written in two columns as 10. Base 4 would use 1, 2 and 3, but no four.

The two-colour afghan shows a pattern of blocks formed by the 1s and 0s of the binary system, from 0 to 31. The 1s have been replaced with pink and the 0s have been replaced with blue. Imagine folding this design top-to-bottom and you will notice the symmetry of the shapes, with the colours reversed. The colours make the pattern very obvious.

In the pastel version the 1s have been coloured, using a different colour in each column. The 0s are all white, to form the background.