Fractions · thirds

What Is 1/3?

1/3 is one third: 1 part out of 3 equal parts.

The short answer

1/3 means 1 out of 3 equal parts. The bottom number (3) says how many equal parts make the whole. The top number (1) says how many you have. As a decimal it's 0.333… (the 3 repeats forever), and as a percent it's about 33.3%.

1/3 in pictures

Pie: 1 of 3 slices
Cake: 1 of 3 parts
Cookies: 1 of 3 on the tray
01/32/31
Number line: one third

1/3 at a glance

In wordsone third
As a decimal0.333… (the 3 repeats forever)
As a percentabout 33.3%
Simplest form1/3 is already in simplest form
Equal fractions2/6, 3/9, 4/12, 5/15
Compared to one halfsmaller than 1/2
Left to make a whole2/3

Is 1/3 in simplest form?

No number bigger than 1 divides both 1 and 3, so 1/3 can't be simplified. It's as simple as it gets.

Fractions equal to 1/3

Multiply the top and bottom by the same number and the amount doesn't change: 1 × 2 = 2 and 3 × 2 = 6, so 1/3 = 2/6. Times 3 gives 3/9. In the bakery, that's the same pie with every slice cut in two, then in three.

More fractions equal to 1/3: 2/6, 3/9, 4/12, 5/15, 6/18. The equivalent fractions lesson shows why this always works.

Is 1/3 bigger than one half?

1/3 is smaller than 1/2. Double the top: 1 × 2 = 2. That's less than the bottom number, 3, so it's under half. Next to its neighbors: 1/3 < 2/3.

1/3 in real life

1/3 of 12 muffins on a rack

Share the 12 into 3 equal groups: 12 ÷ 3 = 4 in each group. Take 1 group: 4 × 1 = 4.

1/3 of an hour

An hour has 60 minutes. 60 ÷ 3 = 20, and 20 × 1 = 20 minutes.

Cutting thirds

Thirds are the awkward cut. Make three cuts from the center, spaced evenly like a Y. Halving won't get you there, because 3 is odd.

Common mix-ups with 1/3

It's not 3/1

Swapping the numbers changes everything. 1/3 is less than one whole; 3/1 is more than one whole. The bottom number always says how many equal parts make up the whole.

It's not 1/2

A pie with 1 filled and 2 empty is not 1/2. That compares the filled part to the empty part. The bottom number counts all 3 parts, filled or not.

Bigger bottom, smaller slice

Kids often think 1/3 beats 1/2 because 3 is the bigger number. It's the other way round: more people sharing one pie means a smaller slice each.

Play with 1/3

Saying a definition doesn't make it stick. Finding 1/3 on a pie, a cake and a number line, over and over, does.

The orders in this game keep coming back to 1/3

Free to play · no signup · works on phones, tablets and computers

Open the game full screen

Quick quiz

1/3 FAQ

What is 1/3 as a decimal?

1/3 = 0.333… Divide the top by the bottom: 1 ÷ 3. The digit 3 repeats forever, so it never ends.

What is 1/3 as a percent?

1/3 is about 33.3%. Percent means "out of 100", so work out 1 ÷ 3 × 100.

What fractions are equal to 1/3?

2/6, 3/9, 4/12, 5/15, 6/18 and many more. Multiply the top and bottom by the same number to make another.

How do you read 1/3 out loud?

Say "one third".

Is the fraction game really free?

Yes. The whole game plays free in your browser, with no signup, no ads and no time limit. A Fraction Bakery app for iPhone is coming later, but the web game stays free.

Take the bakery with you, soon

A Fraction Bakery app for iPhone is on the way. The plan: offline play for the car, a parent report of which fractions have stuck, and the full bakery shelf of prizes. Until then, the whole game is free right here.

Coming soon on theApp Store