Understanding fractions (age 9+)
Understand a fraction a/b with a > 1 as a sum of fractions 1/b (e.g. 3/5 = 1/5 + 1/5 + 1/5)
What a learner can do afterwards
- Express 5/8 as a sum of five copies of 1/8
- Show on a number line how 4/3 is built by iterating 1/3 four times
- Explain why 7/4 = 1/4 + 1/4 + 1/4 + 1/4 + 1/4 + 1/4 + 1/4
1 · Read
You already know that 1/5 means one piece when a whole is cut into 5 equal parts. Today you will see that a fraction like 3/5 is just several of those pieces added up. 3/5 means 1/5 + 1/5 + 1/5.
Look at a number line marked in thirds. Start at 0 and take four hops, each hop the size of 1/3. After four hops you land past one whole, at 4/3.
Any fraction a/b is just a copies of the piece 1/b, added together. The top number tells you how many pieces to add; the bottom number tells you the size of each piece.
A fraction a/b means you add the piece 1/b to itself a times.
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.
18 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.