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What is standard form?

Standard form, or standard index form, is a system of working with, and writing, very large or very small numbers. It is based on using of 10 to express how big or small a number is.

Some numbers may be too big or too small to read or even understand. Writing numbers in standard form makes them easier to comprehend and compare. Also, a calculator may not be able to handle all the numbers in a very large calculation, but by using standard form it can handle numbers of any size.

Scientists use standard form when working with the speed of light and distances between galaxies, which can be enormous. The size of bacteria or atoms may also be referred to in standard form as they are so tiny.

Infographic showing the size of the following in standard form: the Galaxy = 9.5 × 1020 m, planet Earth = 1.3 × 107 m, the Eiffel Tower = 3.2 × 102 m, an atom = 1 × 10-10 m and a hair = 1.8 × 10-5 m.