The goal of this exercise is to understand how to multiply fractions in which the numerical quantities have units. Chemical measurements have units. You will need to label quantities with units and to work with units in your mathematical operations for chemistry problems. In fractions, units are multiplied the same way as the numeric values of the numerators and the denominators. That is, the units of the numerators are multiplied to get the units for the numerator of the answer. Likewise, the units of the denominators are multiplied to get the units for the denominator of the answer. For example, if you are characterizing a span of material that has one atom per three units of length, your calculation would look like: