Question

Solve the following question:

Express the following sum to the appropriate number of significant figures:

319.5 g − 20460 g − 0.0639 g − 45.642 g − 4.173 g

Answer 1

To perform an addition/subtraction operation, first, the numbers are written in such a way that they have the same exponent. The coefficients are then added/subtracted.
319.5 g − 20460 g − 0.0639 g − 45.642 g − 4.173 g
= − 20190.3789 g
= − 20190 g
Sum to the appropriate number of significant figures = − 20190 g