Solving Mixed Number Word Problems Using the Three-Reads Strategy
Students will be able to apply the Three-Reads strategy when solving word problems involving addition and subtraction for unlike mixed numbers.
- Show your class a picture of apples and oranges (there should be a different amount of each) and ask, "How many pieces of fruit are there?"
- After allowing for student responses and confirming the correct amount, ask the class, "How many apples are there?" Allow time for student responses.
- Pose the question, "If there are __ pieces of fruit, and apples are fruit, how come there are different amounts of fruit and apples?"
- Discuss and confirm that although apples are fruit, oranges are also fruit - but because they are different kinds of fruit, they can’t be added all together as one.
- Write the following colloquialism on the board, 'It’s like comparing apples to oranges.' Explain what this figure of speech means, "Although items may belong to the same category, added levels of specificity exist such that items may not be further compared."
- Point out how in the same way, we can’t add mixed numbers with unlike fractions. Even though mixed contain whole numbers, there is an added layer of specificity in the denominators such that unlike fractions can’t be compared.
- Tell your students that today’s lesson will teach a strategy to solve word problems that include mixed numbers with unlike fractions.
Explicit Instruction/Teacher modeling(10 minutes)
- Review the algorithm for converting mixed numbers to improper fractions when adding and subtracting unlike mixed numbers.
- Introduce your students to the Three-Reads strategy, a way of approaching word problems and organizing information (see in Resources section).
- Explain the Three-Reads strategy steps:
- The first read focuses on discovering what the story is about.
- The second read focuses on highlighting quantities in the situation.
- The third read focuses on gathering the math questions; what is being asked?
- Demonstrate the Three Reads strategy with the following word problem:
- Anna bought balloons for Patty Particular’s President’s Day Pizza Party. She purchased 5 2/3 pounds of brilliant baby blue balloons mixed with brown and beige balloons. Unfortunately, Patty Particular’s plans required Anna remove 4 1/4 pounds of the brilliant baby blue balloons. How many pounds of balloons would Anna have left to decorate Patty’s party?
- Sketch a graphic organizer by drawing a three column chart with corresponding labels: What, quantities, and math questions.
- Read the word problem three times, while noting the corresponding information with your students. Remember to solve the problem by converting mixed numbers to improper fractions and performing the applicable function.
Guided Practice(10 minutes)
- Review the algorithm for converting mixed numbers to improper fractions for addition or subtraction as needed, (see the link in the Resources section).
- Hand out and preview the Unlike Your Average Mixed Numbers Word Problems worksheet.
- Have your students draft a Three-Reads graphic organizer and solve the first problem together using the strategy. Answer any clarifying questions.
Independent working time(10 minutes)
- Issue the remaining exercises of Unlike Your Average Mixed Number Word Problems for students to solve.
- Print and post the algorithm for solving addition and subtraction mixed number expressions. (See Resources section.)
- Save and post the guided practice Three-Reads graphic organizer for student reference during independent work time.
- Pull a small group during independent work time and reference the Three Reads guided practice organizer and stage steps for solving word problems.
- Insert double-digit mixed number problems with double-digit denominators.
- Have students draft a poster to illustrate one of the exercises using pictures, symbols, and words.
- A projector, a class whiteboard, and dry-erase markers makes for a great student engagement set-up for demonstrations in front of peers.
- Post two word problems as an exit ticket exercise and have students choose one to solve.
- Collect and review to inform further instruction.
Review and closing(10 minutes)
- Review the exercises from the Unlike Your Average Mixed Number Word Problems worksheet by having students share out their answers and solution details.
- Allow student to "phone a friend" to resume an answer explanation if they get stuck.
- Discuss the following question, “What kinds of clues do sum and difference answers give about their word problems?”
- Note insights on poster paper for future reference.