Transcript Chapter 7.3 Least Common Multiple and Greatest Common

Chapter 7.3
Least Common Multiple and
Greatest Common Factor
MATRIX Grant Project
Tatiana
Jenny
607
Directions
To find LMC you have to list all of the multiples of
the numbers and find the smallest number that
they both have.
Another way to find the LCM is to write the prime
factorizations then write a multiplication problem
using all prime factors once. Then for each factor
write the greatest exponent used with that factor in
any of the prime factorizations. Last multiply.
How to find the GFC list all the factors of each
number find the common factors and then find the
greatest common factors.
Examples
How To Find The LCM
6:6 12 18 24 30 36 42 48 54 60 66 72
3:3 6 9 12 15 18 21 24 27 30 33 36 39
9:9 18 27 36 45 54 63 72 81 90 99 108
The LCM For 6,3,and 9 is 18
Another way to find the LCM is:
6
12
18
6=2x3
/ \
/ \
/\
12=2x2x3
2 3
2 6 3 6
18=2x3x3
/\
/\
it’s 2x3
23
2 3
How to find the GFC
8:1 2 4 8
12:1 2 3 4 6 12 The common factors are 1,2,4 The GCF of 8 and 12 is 4
Problems to solve
List the first 7 Find the LCM
multiples
of the 2
numbers
1) 12
6) 10,20
2) 4
7) 9,7
3) 5
8) 12,18
4) 14
9) 15,30
5) 18
10) 5,6
6) 9
Find the GFC
of the 2
numbers
11) 3,9
12) 21,7
13) 48,72
14) 12,36
15) 6,18
http://www.toonuniversity.com/flash.
asp?err=499&engine=14
In this game 2 numbers are going to
appear on the screen. You are
supposed to find the LCM and GFC
for both numbers
Just like the examples