A fraction with a 1 on top is one single piece.
Unit fraction is a fraction with 1 as the numerator, like 1/4.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
The top number has a name too.
Numerator is the top number. It counts how many parts you have.
Bigger bottom, smaller fraction
1/8 is smaller than 1/4, even though 8 is bigger than 4. More parts means smaller parts.
On the line
1/4 sits a quarter of the way from 0 to 1. That is where its size lives.
One piece out of the whole
A unit fraction has 1 on top: 1/2, 1/3, 1/4, 1/8. It means one of the equal pieces the whole was cut into. The bottom number tells you how many pieces there are altogether, so it also tells you how big each piece is.
A bigger bottom number means a smaller piece
1/8 is smaller than 1/4, even though 8 is bigger than 4. Cutting a cake into more pieces makes each piece smaller. This inverted relationship is the single most confusing thing about fractions and it is worth checking with a real picture every time.
Unit fractions are the building blocks
Every other fraction is made of copies of a unit fraction: 3/4 is three copies of 1/4. Get unit fractions solid and the rest of fractions follows. This is why they are given a lesson of their own.
Step 2: Try It Yourself
Compare two unit fractions. Watch the bigger denominator lose.
1/4
1/8
1/4 is greater than 1/8.
The same number of pieces, but the bigger denominator makes smaller pieces.
Step 3: Watch an Example
One step at a time.
Watch Leo Compare Two Unit Fractions
Leo is asked which is bigger, 1/4 or 1/8.
- Step 1
He notices 8 is bigger than 4 and nearly says 1/8.
Step 4: Your Turn
Practice makes it stick.
Sharing a Cake
Problem 1 of 2
Would you rather have 1/3 of a cake or 1/6 of the same cake?
The Smallest Piece
Problem 2 of 2
Which is the smallest: 1/2, 1/5, or 1/8?
Unit Fractions
1 of 3
Which is bigger, 1/3 or 1/5?
2 of 3
Which is bigger, 1/6 or 1/2?
3 of 3
How many eighths make one whole?
Step 5: Quick Check
Show what you know.
Question 1 of 2
Which is bigger, 1/4 or 1/6?
Question 2 of 2
What does the numerator tell you?
What You Learned
- A unit fraction has 1 on top: one single piece.
- The numerator counts the parts you have.
- A bigger denominator makes a smaller piece.