at 0.29 i didn't understand why we flipped it

Because dividing is the same thing as multiplying by the reciprocal of a number. A reciprocal is basically just a number flipped upside down. Example: 4 ÷ 2 is the same thing as 4 * 1/2.

is there another method to do this

(Prepare for a long answer) Srivish, To answer your question, there IS another way to solve it. Cross multiplication. Here are some steps to help solve it 1: First take your Equation, and if you've already written an answer. Erase it, then write a new set of brackets to have your fractions in. 2: Secondly, take your equation. Let's ignore that division sign for now. So you have your two pairs of fractions, Correct? 3: TO do this, you will have to multiply a bit. First, take the numerator of your first fraction, and multiply it with the denominator of the second Fraction. This will turn into your new Numerator. Now cross off the fractions you just used. 4: Following this, Take your remaining fractions and multiply. This will turn into your new denominator. And complete your answer. However, if your Equation with variables, such as X, the whole question will change. In order to adapt to this, you will have to change the way you solve it. Here is a link detailing how to. https://www.wikihow.com/Cross-Multiply Hope this helps!

oh, my gosh, i was hoping Sal would show us on the number line as is the previous video. i have no problem with solving the problem, but i have no intuitive understanding! in the last video he worked on 8/3 divided by 1/3. it meant we were breaking up 8/3 into segments of 1/3 of a unit each. so we ended up with 8 segments of 1/3 unit, total. i have no idea how to follow that logic for 2/5 divided by 7/3... help, someone? thank you!

Same idea except this time the segment is larger than the initial amount. If we have segments of 7/3 (2 1/3) how many of them make 2/5. In this case you need less than one of them. 6/35 of one in fact. This is because 6/35 of 7/3 equals 2/5.

Do you still have to do the extra math to the side to get the actual answer.

not if you feel like torchuring yourself lol (no seriously, if you dont, it'll take forever to do it).

Main content

Arithmetic

Course: Arithmetic > Unit 15

Lesson 5: Dividing fractions by fractions

Dividing fractions: 2/5 ÷ 7/3

Name: Dividing fractions: 2/5 ÷ 7/3
Uploaded: 2013-12-27T20:42:57Z
Description: Learn to divide two fractions. The answer is a fraction.

CCSS.Math:

6.NS.A.1

Google Classroom

Learn to divide two fractions. The answer is a fraction. Created by Sal Khan.

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e661brown
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can khan academy become drawing academy instesd so we can just take a brake from school
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- RebeccaD
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  No, We need to go to school so we can have a good life. And not a lot of people are good at drawing
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yehhh
Posted 5 years ago. Direct link to yehhh's post “is there another method t...”
is there another method to do this
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- Leon Tong
  Posted 5 years ago. Direct link to Leon Tong's post “(Prepare for a long answe...”
  (Prepare for a long answer) Srivish, To answer your question, there IS another way to solve it. Cross multiplication. Here are some steps to help solve it
  1: First take your Equation, and if you've already written an answer. Erase it, then write a new set of brackets to have your fractions in.
  2: Secondly, take your equation. Let's ignore that division sign for now. So you have your two pairs of fractions, Correct?
  3: TO do this, you will have to multiply a bit. First, take the numerator of your first fraction, and multiply it with the denominator of the second Fraction. This will turn into your new Numerator. Now cross off the fractions you just used.
  4: Following this, Take your remaining fractions and multiply. This will turn into your new denominator. And complete your answer.
  
  However, if your Equation with variables, such as X, the whole question will change. In order to adapt to this, you will have to change the way you solve it. Here is a link detailing how to.
  https://www.wikihow.com/Cross-Multiply
  Hope this helps!
  Comment on Leon Tong's post “(Prepare for a long answe...”
  (17 votes)
sarathomsen24
Posted 5 years ago. Direct link to sarathomsen24's post “at 0.29 i didn't understa...”
at 0.29 i didn't understand why we flipped it
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- [sobbing mathematically]
  Posted 5 years ago. Direct link to [sobbing mathematically]'s post “Because dividing is the s...”
  Because dividing is the same thing as multiplying by the reciprocal of a number. A reciprocal is basically just a number flipped upside down. Example: 4 ÷ 2 is the same thing as 4 * 1/2.
  Comment on [sobbing mathematically]'s post “Because dividing is the s...”
  (5 votes)
Riley Kirshtner
Posted 3 years ago. Direct link to Riley Kirshtner's post “How the _heck_ does a rec...”
How the heck does a reciprocal even work?! I'm mind blown. Can somebody tell me why?
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- AllieM
  Posted 3 months ago. Direct link to AllieM's post “A reciprocal is when you ...”
  A reciprocal is when you flip the numerator and the denominator to get it. So 2/4 would become 4/2, 5/6 would become 6/5, and so forth.
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parkerc3
Posted 4 years ago. Direct link to parkerc3's post “Do you still have to do t...”
Do you still have to do the extra math to the side to get the actual answer.
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- vinc3e
  Posted 3 years ago. Direct link to vinc3e's post “not if you feel like torc...”
  not if you feel like torchuring yourself lol (no seriously, if you dont, it'll take forever to do it).
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Stephen Adebanjo
Posted 10 days ago. Direct link to Stephen Adebanjo's post “There is something that w...”
There is something that we do in our school that is called KCF which means Keep, Change, and Flip we keep the first fraction, change the division sign into a multiplication sign, and flip the denominator and numerator of the second fraction, or you can do the second fractions reciprocal. Hope this helps you the next time you do math!
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d.eileen.d
Posted 5 years ago. Direct link to d.eileen.d's post “oh, my gosh, i was hoping...”
oh, my gosh, i was hoping Sal would show us on the number line as is the previous video. i have no problem with solving the problem, but i have no intuitive understanding! in the last video he worked on 8/3 divided by 1/3. it meant we were breaking up 8/3 into segments of 1/3 of a unit each. so we ended up with 8 segments of 1/3 unit, total. i have no idea how to follow that logic for 2/5 divided by 7/3... help, someone? thank you!
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(1 vote)
Answer
- Mr Levick
  Posted 5 years ago. Direct link to Mr Levick's post “Same idea except this tim...”
  Same idea except this time the segment is larger than the initial amount. If we have segments of 7/3 (2 1/3) how many of them make 2/5. In this case you need less than one of them. 6/35 of one in fact. This is because 6/35 of 7/3 equals 2/5.
  Button navigates to signup page
  (3 votes)
jay.delorenzo
Posted 4 years ago. Direct link to jay.delorenzo's post “how do you know when to c...”
how do you know when to cross multiply
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(2 votes)
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- vinc3e
  Posted 3 years ago. Direct link to vinc3e's post “when it says 2 fractions ...”
  when it says 2 fractions with a multiplication sign next to it. eg: 2/3 X 5/3 is when to cross multiply. :)
  Comment on vinc3e's post “when it says 2 fractions ...”
  (1 vote)
hirt promise
Posted 8 years ago. Direct link to hirt promise's post “I don't get it how do you...”
I don't get it how do you divid fractions
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- Alexis
  Posted 3 years ago. Direct link to Alexis's post “you can just take the fra...”
  you can just take the fraction on the right and switch the two numbers around (so the numerator becomes the denominator and the denominator becomes the numerator) then just multiply the two fractions and you have your answer!
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shouryapatankar09
Posted 3 years ago. Direct link to shouryapatankar09's post “can you just divide first...”
can you just divide first then multipy
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Video transcript

So let's calculate what 2/5 divided by 7/3 is, and I encourage you to pause this video and try to calculate this on your own. Well we just have to remind ourselves that this is going to be the exact same thing as 2 over 5 times the reciprocal of 7/3, which is 3 over 7. And then multiplying two fractions is pretty straightforward. This is just going to be equal to the product of the numerators. So 2 times 3 over the product of the denominators, over 5 times 7-- I'm trying to keep the colors consistent-- which of course is going to be equal to 2 times 3 is equal to 6. And 5 times 7-- I'll do this in a new color, let's see, I haven't used this shade of blue yet-- 5 times 7 of course is equal to 35. So this is equal to 6/35.

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