A rational number can be written exactly in the form \(\frac{a}{b}\), where 𝑎 and 𝑏 are integers, while an irrational number cannot.

These are decimal numbers, and dots above some of the digits make them recurring decimals. One dot means the digit under it repeats infinitely. In other words, it goes on forever (and ever and ever).

THIS is a comprehensive text-book clearly written and well arranged. There is a useful chapter on abridged methods and approximations, and a note (in the appendix) on the metric system. Compound ...