How it is calculated
- Move the decimal point so one non-zero digit is before it, and count the moves as the power of 10
- A number larger than 10 gives a positive power, and a number smaller than 1 gives a negative power
- Digits beyond the chosen significant digits are rounded
- Engineering notation uses a power of 10 that is a multiple of 3
To work with powers, use the exponent calculator. For other maths, use the scientific calculator.
Worked example
- 123456: move the point 5 places, giving 1.23456 × 10⁵
- 0.00045: move the point 4 places to the right, giving 4.5 × 10⁻⁴, which is 450 × 10⁻⁶ in engineering notation
Why your number may differ
Rounding to fewer significant digits changes the value slightly. Computers store numbers with about 15 to 17 significant digits, so very long numbers are shortened.