# How do you determine the number of significant figures in a problem?

##### 1 Answer

As a general rule, use the least number of significant figures present in the given problem/data. More rules follow.

#### Explanation:

Your answer can only be as precise as the least precise measurement!

**1. Least number of significant figures present in given data**

For example, if the problem states that there is 20.0 mL of a 0.10 M Na(OH) solution, your final answer would have 2 significant figures because 20.0 has 3 sig figs and 0.10 only has 2.

**2. When adding/subtracting**

Use the least number of significant figures past the decimal point when adding or subtracting numbers. For example, the answer to 123.45 + 543.2 would have 1 significant figure past the decimal point.

**3. When multiplying/dividing**

Use the least number of significant figures present in *any number* in the problem when multiplying or dividing numbers. For example, the answer to 2.3 x 5.32 would have 2 significant figures in the entire number.