Mixed NumbersMixed Numbers

Mixed numbers are whole Mixed numbers are whole numbers and fractions numbers and fractions together.together.

123

Subtracting Mixed NumbersSubtracting Mixed Numbers

• To subtract mixed numbers, you To subtract mixed numbers, you must make sure the fractions have must make sure the fractions have the same denominator, that’s the the same denominator, that’s the same bottom number. Find the same bottom number. Find the lowest common multiple of the two lowest common multiple of the two denominators. That is the number denominators. That is the number you will use for the denominator in you will use for the denominator in both fractions.both fractions.

Shortcut for Finding the Least Shortcut for Finding the Least Common Denominator or Least Common Denominator or Least

Common MultipleCommon Multiple

1218-

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.

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

3

1

To Subtract Mixed To Subtract Mixed Numbers With Unlike Numbers With Unlike

DenominatorsDenominators• Find the multiples of each Find the multiples of each

denominator.denominator.

1= 4, 8, 12, 16, 20, 24

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

4

10

3

1

To Subtract Mixed To Subtract Mixed Numbers With Unlike Numbers With Unlike

DenominatorsDenominators• Compare the lists of multiples. Compare the lists of multiples.

Circle the common multiples Circle the common multiples between the two lists.between the two lists.

1= 4, 8, 12, 16, 20, 24

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

3

14

To Subtract Mixed To Subtract Mixed Numbers With Unlike Numbers With Unlike

DenominatorsDenominators

1= 4, 8, 12, 16, 20, 24

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

3

14

Use the least commonUse the least common

multiple as the multiple as the denominator.denominator.

To Subtract Mixed To Subtract Mixed Numbers With Unlike Numbers With Unlike

DenominatorsDenominators

1= 4, 8, 12, 16, 20, 24

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

3

14

This number is also calledThis number is also called

the least common the least common denominator.denominator.

To Subtract Mixed To Subtract Mixed Numberss With Unlike Numberss With Unlike

DenominatorsDenominators

1

1- 10

3

14 20

20

• Find the equivalent fractions for Find the equivalent fractions for 1/4 & 1/10 with 20 as the 1/4 & 1/10 with 20 as the denominator.denominator.

Ask yourself whatyou multiply 4 by

to get 20.x 5 =

To Subtract Mixed To Subtract Mixed Numbers With Unlike Numbers With Unlike

DenominatorsDenominators

1

1- 10

3

14 20

20

• Find the equivalent fractions for Find the equivalent fractions for 1/4 & 1/10 with 20 as the 1/4 & 1/10 with 20 as the denominator.denominator.

x 5 =

That’s right 5. Sinceyou are looking for

the equivalent fractionyou know the top

number must also bemultiplied by 5.

x 5 =

To Subtract Mixed To Subtract Mixed Numberss With Unlike Numberss With Unlike

DenominatorsDenominators

1

1- 10

3

14 20

20

• Find the equivalent fractions for Find the equivalent fractions for 1/4 & 1/10 with 20 as the 1/4 & 1/10 with 20 as the denominator.denominator.

x 5 =x 5 = To find the top number

just multiply 1 x 5 toget your equivalent

fraction.

5

To Subtract Mixed To Subtract Mixed Numbers With Unlike Numbers With Unlike

DenominatorsDenominators

1

1- 10

3

14 20

20

• Find the equivalent fractions for Find the equivalent fractions for 1/4 & 1/10 with 20 as the 1/4 & 1/10 with 20 as the denominator.denominator.

x 5 =x 5 = Now ask what you

multiply the 10 byto get 20.

5

x 2 =

To Subtract Mixed To Subtract Mixed Numbers With Unlike Numbers With Unlike

DenominatorsDenominators

1

1- 10

3

14 20

20

• Find the equivalent fractions for Find the equivalent fractions for 1/4 & 1/10 with 20 as the 1/4 & 1/10 with 20 as the denominator.denominator.

x 5 =x 5 = 5

x 2 =

That’s right 2. Since you are looking for the equivalent fraction you know the top number must also be multiplied by 2.

x 2 = 2

To Subtract Mixed To Subtract Mixed Numbers With Unlike Numbers With Unlike

DenominatorsDenominators

1

1- 10

3

1

4 20

20

• Now just subtract the Now just subtract the numerators.numerators.

x 5 =x 5 = 5

x 2 =Remember! We never subtract the denominators.

x 2 = 2

320

To Subtract Mixed To Subtract Mixed Numbers With Unlike Numbers With Unlike

DenominatorsDenominators

1

1- 10

3

1

4 20

20

• Now subtract the whole Now subtract the whole numbers.numbers.

x 5 =x 5 = 5

x 2 =x 2 = 2

3202

Subtract These Mixed Subtract These Mixed NumbersNumbers

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Use the shortcut to find the

Least CommonDenominator

(LCD).

6

6

10

3

Subtract These Mixed Subtract These Mixed NumbersNumbers

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Now find theequivalent

fractions for1/3 & 1/6.

6

6x 1 =

x 2 =

Ask what do you multiply 3 by to get 6and what do you multiply 6 by to get 6.

10

3

Subtract These Mixed Subtract These Mixed NumbersNumbers

1316-

Since you arewriting equivalent

fractions, nowmultiply the topnumbers by the

same number you did in the bottom.

6

6x 1 =

x 2 =x 1 =

x 2 =10

3

Subtract These Mixed Subtract These Mixed NumbersNumbers

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Now multiplyacross.

6

6x 1 =

x 2 =x 1 =

x 2 =

1

210

3

Subtract These Mixed Subtract These Mixed NumbersNumbers

1316-

Subtract yournew

numerators.

6

6x 1 =

x 2 =x 1 =

x 2 =

1

2

16

3

10

Subtract These Mixed Subtract These Mixed NumbersNumbers

1316-

Subtract yourwhole

numbers.

6

6x 1 =

x 2 =x 1 =

x 2 =

1

2

16

3

10

7

Subtract These Mixed Subtract These Mixed NumbersNumbers

1316-

Your answer is:6

6x 1 =

x 2 =x 1 =

x 2 =

1

2

16

3

10

7