A usable fraction is a fraction you can use to measure with (i.e., 1/2, 1/4, 1/8, 1/16 inch). You measure with fractions of an inch. However, your calculator works in decimals of an inch. If you want ...

The fraction may be simplified when the numerator and denominator have a common factor greater than one. Units are often referred to as ones. Eg, 4∙2 has 4 units and 2 tenths, or you could say 4∙2 has ...

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).