Significant Figures

Question

Hi, I do not know the rules on finding the significant figures in combined operation specifically addition and subtraction. Someone let me know and help me. Example is 102.45 + 5.0 - 0.022

Answer 1

When adding and subtracting, the final result can have no more decimal places than the least number of decimal places, in the numbers being added, or subtracted.

Using your example, 102.45 + 5.0 - 0.022 = 107.428, but the 5.0 has only one decimal place. Therefore, the answer can not be known beyond one decimal place, and must be rounded to one decimal place. 107.4