Greatest Common Factor (GCF)

We learned a neat trick for how to quickly get the least common multiple of two numbers, so let's find a similarly easy way to find the greatest common factor of two numbers. Again it involves prime factorization, which of course everyone enjoys.

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[psymcdad]

Just going trough this Playlist of math shows hoch much I've forgotten... And how fun Math can be if it is explained in clean language (as opposed to overly complicated technical terminology as used by teachers that consider math a 'filter' to sort out 'bad students')

[Daviddant]

111 prime factors: {3, 37}
21 prime factors: {3, 7}

multiply common factors 3 X 3 = 9

9 not a factor of either. Why is that?? I'm confused.

[Map-vwqr]

Thank you very much! This helped me a lot with my homework. I just forgot how to get a GFC but, this video reminded me and taught me ever clearer! Thank You just earned a NEW subscriber. Keep up the great work.

[dragonfire_bane]

Do you have a document with the work shown so I can understand it a little better? It would help with the 3rd comprehension question. Otherwise I really like how this is done!

[OquendoMath]

I discovered your videos recently. You teach concepts similarly to how I teach. I love your videos! Thank

[Fayazkhanyt]

hello sir, could you please explain the last two problems. ? I didn't get it

[ignacioleikis]

Are GFCs always smaller (lower in magnitude) than the numbers compared?
Are LCMs always greater or equal than the numbers compared?

[henrychang]

How is this applied in real-life scenarios? What's the use of the GCF?

[davidjohansson]

I want to understand what Dave does differently compared to school to make it so easy to understand. It would be a great skill to have to break complex things like math down to comprehensive portions in a efficient way like these vids.

[yatu]

in india and uk we call it HCF highest common factor

[MiltosPol-qnzh]

I'm looking forward to watching geometry videos

[vdvoskin]

again, there is a much easier way to find the GCF, just keep dividing both members by the same number provided that it yields a whole number, and after, just multiply the numbers that you divided by. For example, 24 and 90: first division is by 3-> 24/3=8 & 90/3=30, second division is by 2-> 8/2=4 & 30/2=15, cannot divide any more, so time to multiply the numbers used to make divisions, which are 3*2=6

[outtathisworldcrazy]

THANKCHU PROF.D!!! THIS IS NOW MY FAV MATH YT

[prplfire]

THANK YOU SO MUCH MR DAVE THIS VIDEO HELPED ME SO MUCH I LEARNED WHAT GCF IS

[BlastMitee]

Thank you mr professor you helped me on my math exam next week 🙏🙏❤️

[azedo]

I’m trying to find where I’m up to in mathematics, and it’s all over the place, I know stuff two years ahead, (like some trigonometry and area of 3D objects) and don’t know some stuff 2 years behind (like my times tables, and long division).

[annapavlova]

Ok i am dumb. I can't get ot. How should i devide the numbers to get all these 2s and 3s? Like i was deviding 24 by 2 and more 2 and more 2, and here it was 2, 3 and 2.... Im confused, totally

[ljr]

In other words, I feel like the operations of LCM is x ∩ y, while the GCF is x ∪ Y?

[Adam-lfhz]

ive become depressed from learning all that me and my peers should’ve years ago

[MiMayonGo]

Never forgive myself how I neglected one of the most critical lesson in mathematics.... Well in algebra