Question

How many significant figures will there be in the answer to the following problem? `6.783 - 2.56`

Answer 1

The answer will be rounded so that it has two decimal places.

Explanation:

When adding or subtracting, the result is rounded so that it has the same number of decimal places as the number in the problem with the least number of decimal places.

`6.783-2.56=4.223`

The answer `4.223` has three significant figures. However, `2.56` has only two decimal places, so `4.223` should be rounded to `4.22`.

Therefore, `6.783-2.56=4.22`.

For more information and practice, go to the following website.
http://www.chemteam.info/SigFigs/SigFigMath-AddSub.html