If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Dividing a unit fraction by a whole number

Learn how to divide fractions by whole numbers. Watch as the instructor visually breaks down a fraction into smaller parts. Then, see practice problems that explain how division changes the value of the original fraction.

Want to join the conversation?

• Good video, but what is the non Common Core way to figure this out? What mathematical formula could be applied to solve this, sans drawing?
• Dividing by a whole number is the same as multiplying by its reciprocal. In this case, dividing by 5 is the same as multiplying by 1/5.

1/3 ÷ 5 is the same as 1/3 x 1/5
Multiply the denominators and numerators.
1/3 ÷ 5 or 1/3 x 1/5 = 1/15
• Hi, I am working with my son to understand fraction division in terms of model. We kind of understand this model well, but when the lower fraction amount is divided by a bigger fraction, how do you model it ? for example 1/5 ÷ 1/2 ?
• draw a fraction diagram of five.Then you take 1/5 and divide it into a half.
• Im confused? what would be the answer for 1/5 diveded my 3 and 3 divided by 1/5?
(1 vote)
• 1/5 divided by 3 can be rewritten as 1/5 times 1/3. To find the product of these, we can multiply the 1 from 1/5 to the 1 from 1/3, and multiply the 5 from 1/5 to the 3 from 1/3 to obtain the fraction 1/15.

Think about it like this: If 1/5 is being divided into 3 smaller parts, then its fraction is going to be 3 times smaller. Essentially the denominator is multiplied by 3.

For the second problem, 3 divided by 1/5 can be rewritten as 3 times 5. Multiply the two together to get your answer, 15.

Think about this one by visualizing 3 as a giant number and a 1/5 as a tiny number considering it's smaller than one. With this in mind, we know that our answer is going to be much larger than 3. Essentially, 3 times 5.

This may look a lot more complicated in the way I explained it, but that's only because I got into the nitty-gritty. It's mostly visualizing, for me at least.
• How would we interpret or understand 1/3 divided by 5?
• Basically you need to make the 5 a fraction, which is 5/1. Then you do 1/3*5 to get 1/15. Then do 1/15 / 1 to get 1/15. Then simplify (if needed, in this problem is not needed). Hope this helps! Please ask any further questions if you need it! :D
• Why is 1/3 divided by 5 equal to 1/15 and not 5/15?
• In fraction division from fraction-whole number you leave numerator un touched
• Does 1/3 divided by 5 = 1/3 times 1/5
• You hit it there. You can just multiply with the periodic break, just as you can divide by the periodic break if you multiply (25 * 1/5 = 25 / 5)