I Hate 'Keep Change Flip' when dividing fractions

Keep change flip is a very easy way to remember how to divide fractions but I believe should only be used once a student has developed a strong understanding of how and why we divide fractions by multiplying

✅How to Multiply and Divide Fractions
✅Add and Subtract Fractions
✅Decimals
✅Numbers and Percents
✅Integer Operations
✅Scientific Notation
✅How to Classify Numbers
✅Prime Factorization

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[PWingert]

Some of us are so old we know Invert and multiply. We were never taught keep change flip!

[KznnyL]

Fantastic explanation! My daughter had problems with KCF. This is so much better!

[waffleisnice]

Wow, i didn't know i need it. Thank you for showing "behind the scene" in maths!

[ruhaansaiyed]

Thank you for this explanation! Also, I think there's an error at the end? 28/3 does not equal 7.

[Reiniedis]

For anyone confused about the end.. he's not trying to reduce it further after 28/15. This is simply the answer to 7/3÷5/4. If you use a calculator to solve 7/3÷5/4 the answer is if you use a calculator to do 28/15 the answer is there is no reducing further, the answer is 28/15. He's just showing how to work the math using fractions, all his math is correct. I hope this helps clear some confusion in the comments.

[TheCrimsonPain]

27 is divisible by 3 which gives you 9 - there was a little confusion at the end

[peterf]

Im not understand how the fraction values can be changed in value as done here with the 5/4 which is 1.25, to 1?
I get the kcf to make the math easier to work with, but not how we can change values of what would have 1.86 if we were to purely divide (7/3)/(5/4) = 1.86
please explain

[shoukatali]

Sir how have you reduced 28/15 as 28 isn't divisible by 3

[olivemd]

Was that a planned error to test if your students were alert? Sometimes the simple things trips one up. I once insisted that 7*2 was 9.

[helloitsmeagain]

He never said that 28/3 equals 7. He was giving a more simple example of why you do not have to write 28/3/1

[MTLTV-eunv]

I agree that we should not teach people to memorize algorithms at a young age. While I, along with a lot of other people, despise Common Core math, I understand and agree with what the intended purpose is (spend more time on why we do something, for example, why the quotient of two fractions is equal to dividend fraction times the reciprocal of the divisor fraction). I think you explain how the gears turn better than the current Common Core standards.

[darrenfalconer]

I thought he would have seen the comments about that mistake by now