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All You Need to Know about LCM & GCF 749 Views


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Description:

This video covers Least Common Multiple and Greatest Common Factor. What are they? How do you find them? How does factorization play in?


Transcript

00:00

Thank you We sneak l c m and g c

00:05

f allah shmoop What are these Mysterious acronyms Top secret

00:10

government organizations A new form of text speak or perhaps

00:14

a misplaced scrabble tiles Actually they're abbreviations for mathematical concepts

00:20

Well l c m is an acronym for least common

00:24

Multiple let's Take a look at that one first Not

00:27

so close Let's Back it up a bit boys Keep

00:29

he beep There there There we go Uh first we

00:33

need to talk about what a multiple is save Got

00:35

the number six multiple is any number that can result

00:38

from multiplying are given number by any other number For

00:41

example you gonna multiply six by one to get six

00:44

by to get twelve Buy three to get eighteen by

00:47

four to get twenty four and so on Six twelve

00:50

eighteen and twenty four are all multiples of six If

00:53

you want to find the multiples of eight you can

00:55

multiply eight by one to get ate by two to

00:58

get sixteen and buy three to get twenty four We

01:01

could keep going but we can see you're in a

01:03

hurry if you want to find the least common multiple

01:05

Of six and a you need to find the smallest

01:08

number that shares both numbers as factors as you can

01:11

see it's unfortunately not as easy as merely multiplying the

01:14

numbers together G c f or greatest common factor is

01:18

basically the reverse When looking for a g c f

01:21

you need to find the largest number that will divide

01:23

evenly into two other Numbers take the numbers 36 and

01:27

forty eight okay wiseguy put him back suppose you're given

01:30

the number of thirty six and forty eight what factors

01:33

that they have in common Well both Numbers are even

01:36

so 2 works three is also a factor as our

01:39

foreign six but the greatest common factor the granddaddy of

01:42

them all is twelve shmoop a good way to find

01:47

the gcs is to first use prime factory ization thirty

01:51

six breaks down into two times two times three times

01:54

three forty eight breaks down into two times two times

01:58

two times two times three the Numbers that the 2

02:02

have in common are the two twos and a three

02:05

multiply those out and voila twelve practice finding l c

02:10

m's and gcs on your own and it will pay

02:12

Dividends Just don't let the catch you Those guys are 00:02:15.828 --> [endTime] not to be trifled with

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