# Word Problems involving Addition and Subtraction of Fractions

These lessons, with videos, examples and step-by-step solutions, help Grade 4 students learn how solve word problems involving addition and subtraction of fractions.

Common Core Standards: 4.NF.3a, 4.NF.3d, 4.NF.1, 4.MD.2

### NYS Common Core Grade 4 Module 5, Lessons 19

Lesson 19 Concept Development

Problem 4: Use the RDW process to solve a word problem involving the subtraction of fractions.
Mrs. Jones had 1 4/8 pizzas left after a party. After giving some to Gary, she had 7/8 pizza left. What fraction of a pizza did she give Gary?

One way is to rewrite the mixed number as 12/8 and subtract. The other method subtracts from the whole and adds back the fractional part.

Lesson 19 Problem Set

Use the RDW process to solve.

1. Sue ran 9/10 mile on Monday and 7/10 mile on Tuesday. How many miles did Sue run in the 2 days?
2. Mr. Salazar cut his son’s birthday cake into equal pieces. Mr. Salazar, Mrs. Salazar, and the birthday boy each ate 1 piece of cake. What fraction of the cake was left?
3. Maria spent 4/7 of her money on a book and saved the rest. What fraction of her money did Maria save?
4. Mrs. Jones had 1 4/8 pizzas left after a party. After giving some to Gary, she had 7/8 pizza left? What fraction of a pizza did she give Gary?
5. A baker had 2 pans of corn bread. He served 1 1/4 pans. What fraction of a pan was left?
6. Marius combined 4/8 gallon of lemonade,3/8 gallon of cranberry juice, and 6/8 gallon of soda water to make a punch for a party. How many gallons of punch did he make in all?

Lesson 19 Homework

Use the RDW process to solve.

1. Isla walked 3/4 mile each way to and from school on Wednesday. How many miles did Isla walk that day?
2. Zach spent 2/3 hour reading on Friday and 1 1/3 hours reading on Saturday. How much more time did he read on Saturday than on Friday?
3. Mrs. Cashmore bought a large melon. She cut a piece that weighed 1 1/8 pounds and gave it to her neighbor. The remaining piece of melon weighed 6/8 pound. How much did the whole melon weigh?
4. Ally’s little sister wanted to help her make some oatmeal cookies. First, she put 5/8 cup of oatmeal in the bowl. Next, she added another 5/8 cup of oatmeal. Finally, she added another 5/8 cup of oatmeal. How much oatmeal did she put in the bowl?
5. Marcia baked 2 pans of brownies. Her family ate 1 5/6 pans. What fraction of a pan of brownies was left?
6. Joanie wrote a letter that was 1 1/4 pages long. Katie wrote a letter that was 3/4 page shorter than Joanie’s letter. How long was Katie’s letter?

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.