This list compares various sizes of positive numbers, including counts of things, dimensionless quantity and probabilities. Each number is given a name in the so called short scale which is used in English speaking countries, as well as a name in the long scale which is used in a series of countries that do not have English as their national language.

Smaller than 10

• Computing: The number 5 × 10 is approximately equal to the smallest positive non-zero value that can be represented by a double-precision IEEE floating-point value.
• Computing: The number 1.4 × 10 is approximately equal to the smallest positive non-zero value that can be represented by a single-precision IEEE floating-point value.

10

(0.000 000 000 000 000 000 000 000 000 001; 1000; short scale: one nonillionth, long scale: one quintillionth)

• Physics: The mass of one electron at rest is 9.109382 × 10 kilogram

10

(0.000 000 000 000 000 000 000 000 001; 1000; short scale: one octillionth, long scale: one quadrilliardth)

• Physics: The mass of one free proton at rest is 1.672621 × 10 kilogram