# WAEC Mathematics Revision Part 2; Logarithms and Surds

With the use of calculators firmly established, logarithmic tables are now rarely used for calculation.

However, the theory of logarithms is important, for there are several mathematical laws that involve the rules of logarithms.

Logarithms having a base of 10 are called common logarithms. There are three laws of logarithms, which can be applied to any Number base.

You should known by now what the nth root of a number means. If the nth root of a number cannot be simplified to a rational number, we call it a surd.

There are several laws that make working with surds easier. I will list them all and then explain where each rule comes from in detail.

It is useful to work with fractions, which have rational denominators instead of surd denominators. It is possible to rewrite any fraction, which has a surd in the denominator as a fraction which has a rational denominator. The following set of examples will show you how this can be achieved.