Least Common Multiple Least Common Denominator

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.

6 = 6, 12, 18, 24, 30, 36

5 = 5, 10, 15, 20, 25, 30

What is the Least Common Multiple of 3

& 8

8 = 8, 16, 24, 32, 40, 48 3 = 3, 6, 9, 12, 15, 21, 24

What is the Least Common Multiple of 4

& 8

8 = 8, 16, 24, 32, 40, 48 4 = 4, 8, 12, 16, 20, 24

What is the Least Common Multiple of 6

& 8

8 = 8, 16, 24, 32, 40, 48 6 = 6, 12, 18, 24, 30, 36

What is the Least Common Multiple of 4

& 10

10 = 10, 20, 30, 40, 50, 4 = 4, 8, 12, 16, 20, 24

What is the Least Common Multiple of 3

& 9

9 = 9, 18, 27, 36, 45, 54 3 = 3, 6, 9, 12, 15, 21,

To Add or Subtract Fractions With Unlike Denominators

• Find the multiples of each denominator.

1= 5, 10, 15, 20, 25, 30

1= 10, 20, 30, 40, 50+

5

10

To Add or Subtract Fractions With Unlike Denominators

• Compare the lists of multiples. Circle the common multiples between the two lists.

15 = 5, 10, 15, 20, 25, 301

10 = 10, 20, 30, 40, 50+

To Add or Subtract Fractions With Unlike Denominators

• Use the lowest common multiple as the denominator.

15 = 5, 10, 15 ,20 ,25 ,301

10 = 10, 20, 30, 40, 50+

To Add or Subtract Fractions With Unlike Denominators

• This number is also called the least common denominator.

15 = 5, 10, 15 ,20 ,25 ,301

10 = 10, 20, 30, 40, 50+

Find the Least Common Denominator or

Least Common Multiple

12 = 2, 4, 6, 8, 10, 1218 = 8, 16, 24, 32, 40+

Find the Least Common Denominator or

Least Common Multiple

110 = 10, 20, 30, 40, 18 = 8, 16, 24, 32, 40+

Find the Least Common Denominator or

Least Common Multiple

110 = 10, 20, 30, 40, 14 = 4, 8, 12, 16, 20, +

Find the Least Common Denominator or

Least Common Multiple

12 = 2, 4, 6, 8, 10, 14 = 4, 8, 12, 16, 20, +

Find the Least Common Denominator or

Least Common Multiple

12 = 2, 4, 6, 8, 10, 12 112 = 12, 24, 36, 48 +

Find the Least Common Denominator or

Least Common Multiple

13 = 3, 6, 9, 12, 15 14 = 4, 8, 12, 16, 20, +

Find the Least Common Denominator or

Least Common Multiple

13 = 3, 6, 9, 12, 15 15 = 5, 10, 15, 20, 25, +

Find the Least Common Denominator or

Least Common Multiple

13 = 3, 6, 9, 12, 15 19 = 9, 18, 27, 36, 45, +

Shortcut for Finding the Least Common Denominator or Least

Common Multiple

1319+

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.

3 will divide evenly into 9, so 9 is your LCD or LCM.

Shortcut for Finding the Least Common Denominator or Least

Common Multiple

1214+

Using the shortcut, what is the LCD or LCM?

2 will divide evenly into 4, so 4 is your LCD or LCM.

Shortcut for Finding the Least Common Denominator or Least

Common Multiple

12110+

Using the shortcut, what is the LCD or LCM?

2 will divide evenly into 10, so 10 is your LCD or LCM.

Shortcut for Finding the Least Common Denominator or Least

Common Multiple

12112+

Using the shortcut, what is the LCD or LCM?

2 will divide evenly into 12, so 12 is your LCD or LCM.

Shortcut for Finding the Least Common Denominator or Least

Common Multiple

1418+

Using the shortcut, what is the LCD or LCM?

4 will divide evenly into 8, so 8 is your LCD or LCM.

Shortcut for Finding the Least Common Denominator or Least

Common Multiple

1316+

Using the shortcut, what is the LCD or LCM?

3 will divide evenly into 6, so 6 is your LCD or LCM.

Shortcut for Finding the Least Common Denominator or Least

Common Multiple

13112+

Using the shortcut, what is the LCD or LCM?

3 will divide evenly into 12, so 12 is your LCD or LCM.

Shortcut for Finding the Least Common Denominator or Least

Common Multiple

13115+

Using the shortcut, what is the LCD or LCM?

3 will divide evenly into 15, so 15 is your LCD or LCM.

Shortcut for Finding the Least Common Denominator or Least

Common Multiple

1318+

Using the shortcut, what is the LCD or LCM?

3 will not divide evenly into 8, so find the least common multiple.