Rounding to significant figures

Rounding to significant figures

1. The first significant figure (sf or sig fig) is the first digit that is not zero. The second, third, forth... significant figures follow on after the first digit. They may or may not be zeros.

   • Examples:
     • 2.7305 has 5 sf
     • 0.00239 has 3 sf

2. To round a number to a given number of significant places, apply the same rules with decimal places. If the next digit is 5 or more, round up.