Question

Khianna wants to make a batch of her Grandma chocolate chip cookies from a friend. The recipe is shown on the recipe card below ( in the photo)
She realizes she only has 1 1/8 cup of brown sugar but plenty of all of he other ingredients. Complete the following to help him determine how she can still make cookies with the recipe

1. What fractional part of the brown sugar needed does she have


3. Fill out the new recipe with the amount of each ingredient ___ cups butter

___ cups flour ___ eggs __tsp baking soda __tsp vanilla ___ cups sugar __1 1/8

___ ounces chocolate chips


How many cookies will the scaled down recipe make? Show your work.

Answer 1

She has 9/8 cups of brown sugar as a fraction.  As a decimal, which is easier to work with here, it is 1.125.  She needs 1.5 cups.  If we set this up as a proportion, we can figure out how many cookies she can make meeting the restriction of brown sugar, and then scale the other ingredients down accordingly.  To figure the number of cookies, our proportion will have brown sugar on top and number of cookies on bottom.  What we are looking for is the number of cookies she can make with 1.125 cups of brown sugar when she can make 24 with 1.5 cups of brown sugar.  $\frac{1.5}{24}= \frac{1.125}{x}$.  Cross multiply to get 1.5x = 27 and x = 18.  She can make 18 cookies.  Now let's backtrack to the ingredients based on the number of cookies we can make.  Set each ingredient up in a proportion with the ingredient on top and the number of cookies on the bottom.  First ingredient you want is flour.  2.25 cups of flour make 24 cookies and we need to find out how much flour will we need to make 18 cookies.  $\frac{2.25}{24}= \frac{x}{18}$.  Cross multiply to get 24x = 40.5 which simplifies to x = 27/16 or 1 11/16 cups of flour.  Do all the ingredients in the same way and you'll be fine!