Dividing Fractions: Keep, Change, Flip
6-8
1
Adding and Subtracting Fractions with Like Denominators
Lesson Details
Grade Level
3-5
Duration (minutes)
1
Summary
A Grade 3-5 math lesson teaching students how to add and subtract fractions that have the same denominator — reviewing numerator and denominator first, then showing that when denominators match, you only add or subtract the numerators and keep the denominator the same, including a simplifying step in the subtraction example.
Student Worksheet: Adding and Subtracting Fractions with Like Denominators
Teacher Note: Students can watch the video lesson above and answer the questions. Click the “Teacher Answer Key” dropdown below when you are ready to review the solutions!
Key Concepts:
• Numerator & Denominator: The numerator (top number) tells how many pieces you have; the denominator (bottom number) tells how many equal pieces make the whole.
• Same Denominator: When two fractions have the same denominator, the pieces are the same size.
• Adding & Subtracting: Add or subtract only the numerators, and keep the denominator the same. Never add or subtract the denominators.
• Simplifying: If the numerator and denominator of your answer share a common factor, divide both by it to simplify the fraction.
Instructions: Read each question carefully and write your answer in the space provided.
- Question 1: In a fraction, what does the numerator tell you? What does the denominator tell you?
- Question 2: Add 1/5 + 2/5. Show your steps.
- Question 3: Why do you keep the denominator the same instead of adding it?
- Question 4: Subtract 4/6 − 1/6. Show your steps before simplifying.
- Question 5: Simplify your answer from Question 4. What number can you divide both the numerator and denominator by?
Click to reveal Teacher Answer Key
1. The numerator tells how many pieces you have. The denominator tells how many equal pieces make the whole.
2. 1 + 2 = 3, keep the denominator 5. Answer: 3/5.
3. Because the size of each piece (the slice size) doesn’t change — only how many pieces you have changes.
4. 4 − 1 = 3, keep the denominator 6. Answer: 3/6.
5. Divide both by 3: 3/6 simplifies to 1/2.
Disclaimer: This worksheet was generated with AI assistance based on original video content. It is intended for educational reference only. Teachers are encouraged to review and adjust questions to fit their curriculum standards before classroom use.
🎯 Extension Activity: Add 2/8 + 3/8, then subtract 7/10 − 3/10. Simplify each answer if possible, and show every step.