where b denotes our base. In other words, it is the coefficients of descending powers of b (i.e. the 1 and 0 above) which, together, form the notation 10. The choice of b itself is up to us, it could be anything. Generally, we use a base of ten (counting with the decimal system) and so 10 denotes the number ten. But, if we want it to, 10 can denote twelve or twenty seven or any number we wish so that, for example,