## Thinking Mathematically (6th Edition)

For 24 brownies, we need: 1 cup of butter 7$\frac{1}{2}$ ounces of unsweetened chocolate 2$\frac{1}{4}$ cups of sugar 3 teaspoons of vanilla 3 eggs 1$\frac{1}{2}$ cups of flour
To convert the recipe for 16 brownies to one that makes 24 brownies, we multiply the amount of each ingredient given for 16 brownies by $\frac{24}{16}$ = $\frac{3}{2}$ (in reduced form). Note 1: All mixed numerals must be converted to an improper fraction prior to multiplying. For example, the 1$\frac{1}{2}$ cups of sugar must be rewritten as the improper fraction of $\frac{3}{2}$. Note 2: Whole numbers, such as 2, must be written as $\frac{2}{1}$ before multiplying. Butter: $\frac{2}{3}$ x $\frac{3}{2}$ = $\frac{6}{6}$ = 1 cup Unsweetened Chocolate: $\frac{5}{1}$ x $\frac{3}{2}$ = $\frac{15}{2}$ = 7$\frac{1}{2}$ ounces (Note: This could also be written in decimal format at 7.5 ounces) Sugar: $\frac{3}{2}$ x $\frac{3}{2}$ = $\frac{9}{4}$ = 2$\frac{1}{4}$ cups Vanilla: $\frac{2}{1}$ x $\frac{3}{2}$ = $\frac{6}{2}$ = 3 teaspoons Eggs: $\frac{2}{1}$ x $\frac{3}{2}$ = $\frac{6}{2}$ = 3 eggs Flour: $\frac{1}{1}$ x $\frac{3}{2}$ = $\frac{3}{2}$ = 1$\frac{1}{2}$ cups