You need no formulas for this problem
Work Step by Step
This problem involves reading a ruler, and it also introduces the idea of sig figs. It first wants us to determine the length of a pencil using a ruler on the page. The pencil is 7.5 cm long. Next it wants us to determine how many sig figs are in this measurement. In a proper measurement, all sig figs will be properly reported. Since this was an easy measurement to take, we can be fairly confident that the measurement has two sig figs. 7 is one, and .5 is the other.