Dividing unit fractions and whole numbers
Solve real-world problems involving division of unit fractions by whole numbers and whole numbers by unit fractions, using visual models and equations
What a learner can do afterwards
- Solve: '3 people share 1/2 lb of chocolate equally — how much each?' (1/6 lb)
- Solve: 'How many 1/3-cup servings in 2 cups of raisins?' (6 servings)
- Create a story context for a given unit-fraction division expression
1 · Read
You already know how to divide by a unit fraction. Now you will use that skill on real problems. Two kinds of stories show up again and again: sharing a small amount equally among people, and figuring out how many small scoops fit inside a bigger amount.
3 people share 1/2 lb of chocolate equally. That is a sharing story, so divide the unit fraction by the whole number: 1/2 ÷ 3 = 1/6. Each person gets 1/6 lb.
You want to scoop 1/3-cup servings out of 2 cups of raisins. That is a scooping story, so divide the whole number by the unit fraction: 2 ÷ 1/3 = 6. You get 6 servings.
Ask yourself which story you are in. Splitting a small amount among people? Divide the fraction by the whole number. Filling scoops from a bigger amount? Divide the whole number by the fraction.
Same fraction-division skill, two stories: split a small amount among people, or count how many scoops fill a bigger amount.
2 · Watch
Take it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
16 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.