## Chemistry 9th Edition

Significant figures contain all of the certain digits and the first uncertain digit (the first estimated digit) of a number. This is how to write 1000 in different significant figures: - 1 significant figure: 1000 or 1 × $10^{3}$ - 2 significant figures: 1.0 × $10^{3}$ - 3 significant figures: 1.00 × $10^{3}$ - 4 significant figures: 1000. or 1.000 × $10^{3}$ The answer cant be 1.0 since 1.0 has 2 significant figures while the actual answer (which is 1) has only 1 significant figure.
Significant figures contain all of the certain digits and the first uncertain digit (the first estimated digit) of a number. To perform the calculation for the following operation $$\frac{1.5-1.0}{0.50}$$ We first have to consider the addition/subtraction significant figure rule. It is applied to 1.5 −1.0. The result of this is 0.5, which is a one significant figure answer. Next, the multiplication/division rule is applied to 0.5/0.50. A one significant figure number divided by a two significant figure number yields an answer with one significant figure. The answer should therefore be 1.