We have seen that the relation which the upper scales bear to the lower
set is such that over any number on D is its square on A, and,
conversely, under any number on A is its square root on D, the same
remarks applying to the C and B scales on the slide. Taking the values
engraved on the rule, we have on D, numbers lying between 1 and 10, and
on A the corresponding squares extending from 1 to 100. Hence the
squares of numbers between 1 and 10, or the roots of numbers between 1
and 100, can be read off on the rule by the aid of the cursor. All other
cases are brought within these ranges of values by factorising with
powers of 10, as before explained.