## Elementary Algebra

Three cakes need $\frac{9}{4}$ cups of sugar.
One birthday cake calls for $\frac{3}{4}$ cups of sugar. To make 3 cakes, we multiply $\frac{3}{4}$ by 3. So, $\frac{3}{4}$ $\times$ 3 = $\frac{3\ \times 3}{4}$ = $\frac{9}{4}$ cups of sugar Three cakes need $\frac{9}{4}$ cups of sugar.