Scientific Notation

Huge and tiny numbers get tamed by scientific notation: a value between 1 and 10, times a power of 10. The speed of light is about 3.0 × 10⁸ meters per second. A hydrogen atom is roughly 1.2 × 10⁻¹⁰ meters across. The compact form keeps you from miscounting a long string of zeros.

The exponent is really just a zero-counter. 10³ means 1 followed by three zeros, or 1,000; 10⁶ is a million. A negative exponent counts the other way: 10⁻³ is 0.001, three places to the right of the decimal. Read the exponent and you instantly know the size, without ever writing the zeros out.