Madeline Hunter lesson plan
Adding fractions with unlike denominators
| Subject | Math | Grade | 5 |
|---|---|---|---|
| Date | Length | 50 minutes |
Standards
CCSS.MATH.CONTENT.5.NF.A.1 (add and subtract fractions with unlike denominators by replacing them with equivalent fractions).
Objective
Students will be able to add two fractions with unlike denominators by finding a common denominator, with 4 of 5 problems correct.
Purpose
Recipes, measurements and sports stats often mix halves, thirds and quarters. Today you'll learn how to add them.
Materials and resources
Fraction strips, mini whiteboards, practice sheet (10 problems), slide with recipe problem
Anticipatory set (5 min)
Recipe problem: "A smoothie needs 1/2 cup of yogurt and 1/3 cup of milk. How much liquid is that?" Students estimate: more or less than 1 cup?
Input (8 min)
Review equivalent fractions. Show why 1/2 + 1/3 is not 2/5 using fraction strips. Introduce the steps: find a common denominator, rename, add numerators, simplify.
Modeling (7 min)
Think aloud through 1/2 + 1/3 and 3/4 + 1/6 using strips, then the number line, then numbers only.
Check for understanding
Whiteboards: "What common denominator would you use for 2/3 + 1/4?" Hold up on the count of three. Re-teach with strips if fewer than 80% are correct.
Guided practice (12 min)
Pairs solve three problems; one partner explains each step out loud. Teacher circulates and gives feedback.
Closure (5 min)
Students write the steps in their own words on a sticky note and add one example.
Independent practice (13 min)
Practice sheet problems 1–10 (in class; finish for homework).
Differentiation and accommodations
Support: fraction strips available throughout; problems where one denominator is a multiple of the other. Extension: add three fractions; write a word problem for a partner.
Planned time: 50 minutes of 50