# What rule does Empower use for rounding significant digits? - WKB2758

Article number: 2758

## ENVIRONMENT

- Empower

## ANSWER

When rounding is required, Empower looks at the digit in the decimal place to the right of the specified precision in the unrounded number.

- If this digit is less than than five, it and all digits to its right are eliminated and the preceding digit remains unchanged.
- If this digit is equal to or greater than five, it and all digits to its right are eliminated and the preceding digit is increased by 1.

For example, with a specified precision of 4, the number 7.2525515 would be rounded up to 7.2526, while the number 7.2525415 would be rounded down to 7.2525.

Empower uses the printf functionality in C++ for rounding.

For reference, the USP Rounding Rules are as follows:

When rounding is required, consider only one digit in the decimal place to the right of the last place in the limit expression. If this digit is less than five, it is eliminated and the preceding digit is unchanged. If this digit is equal to or greater than five, it is eliminated and the preceding digit is increased by 1.