Final answer:
Linda's baking requires her to calculate the total sugar needed for a cake and cookies, utilizing addition and subtraction of fractions. She starts with 1/4 cup, and after calculating, realizes she needs 2 more cups to meet the recipe requirements.
Step-by-step explanation:
Here's a real-world problem involving addition and subtraction of rational numbers:
Linda is baking a cake and a batch of cookies. The cake recipe calls for 1 1/2 cups of sugar, while the cookie recipe needs 3/4 of a cup of sugar. She already has 1/4 cup of sugar in a bowl. How much more sugar does she need to combine with that to have enough for both recipes?
To solve this problem, you would:
- Add the amounts of sugar needed for the cake and cookies: 1 1/2 cups + 3/4 cup = 2 1/4 cups.
- Subtract the sugar Linda already has from the total amount needed: 2 1/4 cups - 1/4 cup = 2 cups.
Linda needs to add 2 more cups of sugar to the quarter-cup she already has.
This exercise demonstrates how intuitive understanding of fractions and operations with rational numbers can be applied to everyday cooking scenarios, with the addition and subtraction of fractions being used to calculate total ingredients.