Adding and Subtracting Fractions with Same Denominators
Adding and Subtracting Fractions with Same Denominators
Learning Standards
Content Standard
The learner demonstrates understanding of addition and subtraction of fractions
Performance Standard
The learner is able to apply knowledge of fractions in mathematical problems and real-life situations
Learning Competency
Visualizes addition and subtraction of similar fractions using models and manipulatives
Code: M4NS-IIc-81.1
Complete Lesson Plan
Learning Objectives
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Visualize addition of fractions with same denominators using concrete materials and illustrations
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Add fractions with same denominators accurately
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Subtract fractions with same denominators correctly
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Solve word problems involving addition and subtraction of similar fractions
Lesson Procedures
motivation
Show a pizza divided into 8 equal slices. Ask: 'If you ate 2 slices and your friend ate 3 slices, how many slices were eaten altogether? How can we write this using fractions?'
presentation
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Present the problem: Maria ate 2/8 of a pizza and Juan ate 3/8 of the same pizza. What part of the pizza did they eat altogether?
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Use fraction circles to visualize: Show 2/8 (2 shaded parts) + 3/8 (3 more shaded parts)
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Guide students to observe that we add the numerators: 2 + 3 = 5
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The denominator stays the same: 8
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Therefore: 2/8 + 3/8 = 5/8
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Explain the rule: When adding fractions with the same denominator, add the numerators and copy the denominator
generalization
Ask students:
- How do we add fractions with the same denominator?
- How do we subtract fractions with the same denominator?
- Why do we keep the denominator the same?
- When should we simplify our answers?
guided practice
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Work together on these examples:
- 3/10 + 4/10 = 7/10
- 5/12 + 2/12 = 7/12
- 1/6 + 3/6 = 4/6 = 2/3 (simplified)
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Introduce subtraction using a similar approach: Juan had 7/8 of a chocolate bar. He gave 3/8 to his sister. How much does he have left?
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Demonstrate: 7/8 - 3/8 = 4/8 = 1/2 (simplified)
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State the rule: When subtracting fractions with the same denominator, subtract the numerators and copy the denominator
independent practice
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Solve these problems in your notebooks:
Addition:
- 2/7 + 3/7 = ____
- 4/9 + 3/9 = ____
- 1/5 + 2/5 = ____
Subtraction: 4. 6/10 - 2/10 = ____ 5. 8/12 - 5/12 = ____ 6. 5/6 - 2/6 = ____
preliminary activities
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Prayer and greetings
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Checking of attendance
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Review of previous lesson on fractions and their parts
Assessment
answers
- 7/8
- 11/12
- 5/10 = 1/2
- 5/9
- 3/8 meter
evaluation
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Solve the following:
- 3/8 + 4/8 = ____
- 5/12 + 6/12 = ____
- 9/10 - 4/10 = ____
- 7/9 - 2/9 = ____
- Word Problem: Ana bought 5/8 meter of ribbon. She used 2/8 meter for her project. How much ribbon does she have left?
Materials & Resources
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Fraction bars and circles
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Manila paper and markers
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Flashcards with fraction problems
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PowerPoint presentation
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Student worksheets
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Visual aids (pizza, chocolate bar illustrations)
assignment
Homework:
- Create 3 addition problems and 3 subtraction problems using fractions with the same denominator
- Draw illustrations to show your answers
- Practice simplifying your answers
Remarks:
- Observe which students need additional support with the concept
- Note students who can work independently
- Prepare remedial activities for those who struggle
subject matter
Topic: Adding and Subtracting Fractions with Same Denominators
Key Concepts:
- Similar fractions are fractions with the same denominator
- When adding similar fractions, add only the numerators and keep the denominator the same
- When subtracting similar fractions, subtract only the numerators and keep the denominator the same
- Express answers in simplest form
Materials:
- Fraction bars/circles
- Manila paper
- Marker pens
- Flashcards with fractions
- PowerPoint presentation on fractions