Transcript Fraction IX Least Common Multiple Least Common Denominator

Fraction IX
Least Common Multiple
Least Common
Denominator
By Monica Yuskaitis
Product

The answer to a multiplication
problem.
6 X 6 = 36
What is the product?
7 X 8 = 56
What is the product?
8 X 9 = 72
Multiple

The product of a whole number
multiplied times any other whole
number.
Some multiples of 6
6, 12, 18, 24, 30, 36, 42
Name some multiples of 5
5, 10, 15, 20, 25, 30, 35
Name some multiples of 7
7, 14, 21, 28, 35, 42, 49
Name some multiples of 4
4, 8, 12, 16, 20, 24, 28
Name some multiples of 9
9, 18, 27, 36, 45, 54, 63
Common Multiple

A number that is a multiple
of two or more numbers.
Some multiples of 3 & 6
6, 12, 18, 24, 30, 36, 42
What are some Common
Multiples for 2 & 8?
8, 16, 24, 32, 40, 48, 56
What are some Common
Multiples for 4 & 6?
12, 24, 36, 48, 56, 60
What are some Common
Multiples for 3 & 7?
21, 42, 63
What are some Common
Multiples for 5 & 10?
10, 20, 30, 40, 50, 60
Least Common Multiple

The smallest common multiple
of a set of two or more
numbers.
5 = 5, 10, 15, 20, 25, 30
6 = 6, 12, 18, 24, 30, 36
What is the Least Common
Multiple of 3 & 8
3 = 3, 6, 9, 12, 15, 21, 24
8 = 8, 16, 24, 32, 40, 48
What is the Least Common
Multiple of 4 & 8
4 = 4, 8, 12, 16, 20, 24
8 = 8, 16, 24, 32, 40, 48
What is the Least Common
Multiple of 6 & 8
6 = 6, 12, 18, 24, 30, 36
8 = 8, 16, 24, 32, 40, 48
What is the Least Common
Multiple of 4 & 10
4 = 4, 8, 12, 16, 20, 24
10 = 10, 20, 30, 40, 50,
What is the Least Common
Multiple of 3 & 9
3 = 3, 6, 9, 12, 15, 21,
9 = 9, 18, 27, 36, 45, 54
To Add or Subtract Fractions
With Unlike Denominators

Find the multiples of each
denominator.
1
5 = 5, 10, 15, 20, 25, 30
1
+10 = 10, 20, 30, 40, 50
To Add or Subtract Fractions
With Unlike Denominators

Compare the lists of multiples.
Circle the common multiples
between the two lists.
1
5 = 5, 10, 15, 20, 25, 30
1
+10 = 10, 20, 30, 40, 50
To Add or Subtract Fractions
With Unlike Denominators

Use the lowest common
multiple as the denominator.
1
5 = 5, 10, 15 ,20 ,25 ,30
1
+10 = 10, 20, 30, 40, 50
To Add or Subtract Fractions
With Unlike Denominators

This number is also called the
least common denominator.
1
5 = 5, 10, 15 ,20 ,25 ,30
1
+10 = 10, 20, 30, 40, 50
Find the Least Common
Denominator or Least Common
Multiple
1
2 = 2, 4, 6, 8, 10, 12
1
+ 8 = 8, 16, 24, 32, 40
Find the Least Common
Denominator or Least Common
Multiple
1
10 = 10, 20, 30, 40,
1
+ 8 = 8, 16, 24, 32, 40
Find the Least Common
Denominator or Least Common
Multiple
1
10 = 10, 20, 30, 40,
1
+ 4 = 4, 8, 12, 16, 20,
Find the Least Common
Denominator or Least Common
Multiple
1
2 = 2, 4, 6, 8, 10,
1
+ 4 = 4, 8, 12, 16, 20,
Find the Least Common
Denominator or Least Common
Multiple
1
2 = 2, 4, 6, 8, 10, 12
1
+ 12 = 12, 24, 36, 48
Find the Least Common
Denominator or Least Common
Multiple
1
3 = 3, 6, 9, 12, 15
1
+ 4 = 4, 8, 12, 16, 20,
Find the Least Common
Denominator or Least Common
Multiple
1
3 = 3, 6, 9, 12, 15
1
+ 5 = 5, 10, 15, 20, 25,
Find the Least Common
Denominator or Least Common
Multiple
1
3 = 3, 6, 9, 12, 15
1
+ 9 = 9, 18, 27, 36, 45,
Shortcut for Finding the Least
Common Denominator or Least
Common Multiple
Check to see if the smaller denominator
divides evenly into the larger denominator.
If it does, use the larger denominator for
your LCD or LCM.
1
3
1
+ 9
3 will divide evenly into 9,
so 9 is your LCD or LCM.
Shortcut for Finding the Least
Common Denominator or Least
Common Multiple
Using the shortcut, what is the LCD or
LCM?
1
2
1
+ 4
2 will divide evenly into 4,
so 4 is your LCD or LCM.
Shortcut for Finding the Least
Common Denominator or Least
Common Multiple
Using the shortcut, what is the LCD or
LCM?
1 2 will divide evenly into 10,
2 so 10 is your LCD or LCM.
1
+ 10
Shortcut for Finding the Least
Common Denominator or Least
Common Multiple
Using the shortcut, what is the LCD or
LCM?
1 2 will divide evenly into 12,
2 so 12 is your LCD or LCM.
1
+ 12
Shortcut for Finding the Least
Common Denominator or Least
Common Multiple
Using the shortcut, what is the LCD or
LCM?
1
4
1
+ 8
4 will divide evenly into 8,
so 8 is your LCD or LCM.
Shortcut for Finding the Least
Common Denominator or Least
Common Multiple
Using the shortcut, what is the LCD or
LCM?
1
3
1
+ 6
3 will divide evenly into 6,
so 6 is your LCD or LCM.
Shortcut for Finding the Least
Common Denominator or Least
Common Multiple
Using the shortcut, what is the LCD or
LCM?
1 3 will divide evenly into 12,
3 so 12 is your LCD or LCM.
1
+ 12
Shortcut for Finding the Least
Common Denominator or Least
Common Multiple
Using the shortcut, what is the LCD or
LCM?
1 3 will divide evenly into 15,
3 so 15 is your LCD or LCM.
1
+ 15
Shortcut for Finding the Least
Common Denominator or Least
Common Multiple
Using the shortcut, what is the LCD or
LCM?
1
3
1
+ 8
3 will not divide evenly into
8, so find the least common
multiple.