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')
That had me scratching my head for a while too. I eventually realized that there's only one 3 between both sides, not two. The two 3's you end up with sort of combine to represent a 3 that's common to both sides. So you end up with 3, not 3 x 3. Not sure if that explanation makes sense.
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!!!!!! You just earned a NEW subscriber. Keep up the great work.
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!
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
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.
I think it’s more so that math is relatively easy if you learn the concepts step by step but schools fail to teach or students fall behind and then struggle later on with comprehending the concepts.I mostly use these videos as a review so I don’t get left behind because of some slight issue that I didn’t notice previously
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).
@@collectersaab actually i just got it, there is only one couple of the number 3, so it's just 3, to have 3x3 we would need four primes of the number 3 (two couples) to make 3x3, because for each couple you write the number once.
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
Finding GCD is indeed easier with Euclids method if your good with calculating big numbers in head or using a calculator. I find this method easier because since you break it up into smaller numbers. I found this video that instructs how to use Euclids to find first GCD and then LCM: ruclips.net/video/89mJLJjL6YQ/видео.html
I must correct myself on which is easier or better. On the comprehension test 24 and 90 was easier with shown method. But with the 72 and 168 it was easier for me with the Euclidean. For the 21 and 111 Euclidean was easier because it was kinda hard to figure out 3 * 37 and then finding out that 37 is a prime! The last one was very fast and easy with Euclid method! Check out this video for an example with Euclid GCD: ruclips.net/video/fwuj4yzoX1o/видео.html
Goddamn, why is number theory such an early topic in mathematics, it throws me off so bad, LCM and LCD, urghhhh. It relies so heavily on memorisation of times tables to execute this stuff quickly so I am terrible at it
because he explains what you need to know and why we need to know it rather than in class teachers, they can say the most arbitrary things and just expect the student to absorb it.
In both my grammar school education, and on every advanced calculator that I've seen and worked with, it is called the Greatest Common DENOMINATOR (GCD), and not the Greatest Common FACTOR (GCF)... Just pointing that out...
I know you probably don't need this answer anymore but i was just stuck on this too before realizing i missed 5 while calculating the prime numbers of 800 making 16x5=80
(m+n)²=m²+n² m²+2mn+n²=m²+n² 2mn=0 mn=0 You're given (3^m)^n which is equal to 3^(mn) by exponent rules. Because mn=0, you get 3^(mn)=3^0=1 and that's your answer.
![Learn Greatest Common Factor (GCF) & Least Common Multiple (LCM) - [7]](http://i.ytimg.com/vi/W0ZQZtbq01c/mqdefault.jpg)
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')
BINGO!!!!
how*
through*
THIS!! so glad i’m not alone on this one
You're also not distracted by other hot/funny students around you when you're watching this.
You all like 16? I’m in year three
8 years old
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.
That had me scratching my head for a while too. I eventually realized that there's only one 3 between both sides, not two. The two 3's you end up with sort of combine to represent a 3 that's common to both sides. So you end up with 3, not 3 x 3. Not sure if that explanation makes sense.
@@dontstealmydiamondsv3156 thanks dude, now that seems kinda obvious but I'll let this comment here just in case someone make the same mistake.
@@dontstealmydiamondsv3156 thanks, brother, I feel like l I love you and I'm not gay 😂
@@Daviddant100 glad u kept it here, not the same issue but simmilar
Yep I feel dumb now😂 If anyone is still wondering, you only multiply the prime numbers ONCE per common prime number. So 3 x 1 = 3, in this instance.
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!!!!!! You just earned a NEW subscriber. Keep up the great work.
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!
I discovered your videos recently. You teach concepts similarly to how I teach. I love your videos! Thank youuuuu
hello sir, could you please explain the last two problems. ? I didn't get it
Are GFCs always smaller (lower in magnitude) than the numbers compared?
Are LCMs always greater or equal than the numbers compared?
yep
@@ProfessorDaveExplains Awesome, thanks!
@@ignacioleikis1784 The GCF can be equal to both numbers
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
That's actually the same. Prime factors are factors of both members, and then you just multiply the common factors of both.
thanks
It doesnt work with 111 and 21 though
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.
I think it’s more so that math is relatively easy if you learn the concepts step by step but schools fail to teach or students fall behind and then struggle later on with comprehending the concepts.I mostly use these videos as a review so I don’t get left behind because of some slight issue that I didn’t notice previously
THANKCHU PROF.D!!! THIS IS NOW MY FAV MATH YT CHANNEL!!!!!!!!!!!!!
in india and uk we call it HCF highest common factor
In Nigeria we call it hcf too
How is this applied in real-life scenarios? What's the use of the GCF?
It's for fun
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).
ive become depressed from learning all that me and my peers should’ve years ago
Never forgive myself how I neglected one of the most critical lesson in mathematics.... Well in algebra
Fr
I was so dumb at math now im mathematician:) never give up
I'm looking forward to watching geometry videos
coming very soon! already filmed and everything.
Great!
In other words, I feel like the operations of LCM is x ∩ y, while the GCF is x ∪ Y?
THANK YOU SO MUCH!!!
谢谢你帮我math我簇生在中国thankyouverymuch sorry if ima wrong mrpoffesor davee!!!
THANK YOU SO MUCH MR DAVE THIS VIDEO HELPED ME SO MUCH I LEARNED WHAT GCF IS WHOOOOOHOOOOOO
get him to 1mil pls
This was very helpful.
Thankyou.
Thank you mr professor you helped me on my math exam next week 🙏🙏❤️
Why the gcf of 21 and 111 not 9?
Did you get the reason for the answer? Still trying to find out.. thanks..
@@Dan_Afriat No, still didn't get it.
@@collectersaab actually i just got it, there is only one couple of the number 3, so it's just 3, to have 3x3 we would need four primes of the number 3 (two couples) to make 3x3, because for each couple you write the number once.
@@Dan_Afriat Alright, Thanks.
@@Dan_Afriat thank you sm. I have no idea why i did that mistake haha
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
Maybe I'm late to reply to this but you should watch his video about prime factorization.
What is the GCF of 8xy²?
you need to be comparing two terms to get a GCF
I'm not a big fan of using the prime factorization...
108=4*24+12
24=2*12+0
answer = 12
well, 12 is the right answer, so even though your equations seem odd to me you arrived at the right answer, might be a good strategy!
Professor Dave Explains it is the Euclidean Algorithm.
Finding GCD is indeed easier with Euclids method if your good with calculating big numbers in head or using a calculator. I find this method easier because since you break it up into smaller numbers.
I found this video that instructs how to use Euclids to find first GCD and then LCM:
ruclips.net/video/89mJLJjL6YQ/видео.html
I must correct myself on which is easier or better.
On the comprehension test 24 and 90 was easier with shown method.
But with the 72 and 168 it was easier for me with the Euclidean.
For the 21 and 111 Euclidean was easier because it was kinda hard to figure out 3 * 37 and then finding out that 37 is a prime!
The last one was very fast and easy with Euclid method!
Check out this video for an example with Euclid GCD: ruclips.net/video/fwuj4yzoX1o/видео.html
Goddamn, why is number theory such an early topic in mathematics, it throws me off so bad, LCM and LCD, urghhhh.
It relies so heavily on memorisation of times tables to execute this stuff quickly so I am terrible at it
Thank you its very helpful
That 111 was hard! 😬
I split 111 into 3 x 37, and currently struggling to split 37. How did you do it? ;_;
@@shahadabdulaziz7339 i think 37 is a prime
Yeah lol I solved it. It was 3. Thanks for help though! You'll see me in the comment section of this playlist quite often ^_^
@@shahadabdulaziz7339 I'm currently in binomials
@@zerosandones7547 Good luck! I'm trying to get to Calculus
Thank you, Professor!
Thank you prof.
2:30
We missed how you started teaching us the importance of what we study in our lives
Thanks a lot
Thank you
Is it just me? Cause I feel like I learned more in a 4+ minute video than when I sat for an hour math class when I was in grade school.
because he explains what you need to know and why we need to know it rather than in class teachers, they can say the most arbitrary things and just expect the student to absorb it.
ACTUALLY IT IS ALSO CALLED AS HCF HIGHEST COMMON FACTOR
ACTUALLY synonyms exist
I`m amazed. !!!
In both my grammar school education, and on every advanced calculator that I've seen and worked with, it is called the Greatest Common DENOMINATOR (GCD), and not the Greatest Common FACTOR (GCF)... Just pointing that out...
How is the 720 and 800 not 16??
I know you probably don't need this answer anymore but i was just stuck on this too before realizing i missed 5 while calculating the prime numbers of 800 making 16x5=80
tanks master
The theme song hita different
and this just seems like &ing?
Cool math
I'm kinda angry about the fact that our teacher never taught us this back in school. Ugh...
❤❤❤
*The greatest common multiplier of 21 and 111 Isn't it 21?*
21= 3*7
111= 3*37
So 3,7 and 3, 37
There is only the 3 pair up
❤
Williams Michelle Taylor Steven Gonzalez Cynthia
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no hate this guy but HOW DOES HE have 1 million subscribers
Take a look around my channel, bud.
Better question would be how does he have ONLY a million subscribers.
You are extraordinary than all tutor teachers I do admired please sir help me solve this question if (m+n)^2=m^2+n^2 ,what is (3^m)^n
(m+n)²=m²+n²
m²+2mn+n²=m²+n²
2mn=0
mn=0
You're given
(3^m)^n which is equal to 3^(mn) by exponent rules. Because mn=0, you get 3^(mn)=3^0=1 and that's your answer.
is 72 and 68 gcf is 4