RN Subtracting Mixed Fractions
The least common denominator for this problem is

To subtract mixed fractions, the first step is to find the

common denominator and make new equivalent

fractions.  To find the common denominator, list

the multiples of the denominators until you find a

common one.

3:  3, 6, 9, 12, 15, 18, 21, ...

7:  7, 14, 21, 28, 35, ...

-

5

2

1

5

7

3

After this you make new equivalent fractions with the

common denominator.

-

5

2

1

5

7

3

x 3
x 3
x 7
x 7

=

=

5

2

21

21

15

Now subtract whole numbers and numerators.  Never

subtract denominators. 

-

5

2

1

5

7

3

x 3
x 3
x 7
x 7

=

=

5

2

3

21

21

 7

21

15

The least common denominator for this problem is

To subtract mixed fractions, the first step is to find the

common denominator and make new equivalent

fractions.  To find the common denominator, list

the multiples of the denominators until you find a

common one.

3:  3, 6, 9, 12, 15....

4:  4, 8, 12, 16, 20...

-

5

4
3

2

3

4

After this you make new equivalent fractions with the

common denominator.

-

5

4
3

2

3

4

x 4 
x 4 
x 3 
x 3 

=

=

5

4

12

12

8

-

Now subtract whole numbers and numerators.  Never

subtract denominators.  However, on this problem

we can not subtract 9 from 8 so we have to take one

from the 5 and rename it to 12/12s.

5

4
final answer

12

12

9

8

=

4

+

12

12

+

12

8

=

-

4

4

20

12

12

12

9

The least common denominator for this problem is

To subtract mixed fractions, the first step is to find the

common denominator and make new equivalent

fractions.  To find the common denominator, list

the multiples of the denominators until you find a

common one.

New problem.

5:  5, 10, 15, 20,...

3:  3, 6, 9, 12, 15,...

-

7

4

2

2

5

3

After this you make new equivalent fractions with the

common denominator.

-

7

4

2

2

5

3

x 3 
x 3
x 5
x 5 

=

=

7

4

15

15

6

-

Now subtract whole numbers and numerators.  Never

subtract denominators.  However, on this problem

we can not subtract 10 from 6 so we have to take one

from the 7 and rename it.

Make sure the final answer is simplified.

7

4

10

15

15

6

=

6

+

15

15

+

15

6

=

-

2

6

4

10

21

15

15

15

The least common denominator for this problem is

To subtract mixed fractions, the first step is to find the

common denominator and make new equivalent

fractions.  To find the common denominator, list

the multiples of the denominators until you find a

common one.

4:  4, 8, 12, ...

2:  2, 4, ...

-

5

3

1

1

4

2

After this you make new equivalent fractions with the

common denominator.

-

5

3

1

1

4

2

x 2
x 2

=

=

5

3

 4

1

4

-

Now subtract whole numbers and numerators.  Never

subtract denominators.  Here again we can not subtract

2 from 1 so we take from the whole number.

5

3

 4

 4

2

1

=

4

+

 4

 4

+

 4

1

=

-

1

4

3

 5

 4

 4

 4

2

-

New problem!

Think money!  Could we take 3 dollars and 3 quarters

away from 5 dollars?  No!  We would need change.

How many quarters would we get for one dollar?

5

3

 4

3

=

4

+

 4

 4

=

-

4

3

1

 4

 4

 4

 4

3

Think money!  Could we take 3 dollars and 3 quarters

away from $5 and one quarter?  No!  We would need

change.  How many quarters would we get for one

dollar?  How many quarters did we already have?

-

Make sure its simplified.

5

3

 4

 4

1

3

=

4

+

 4

 4

+

 4

1

=

-

4

3

1

 5

 4

 4

 4

3

=

1

2

-

Now you solve.

2

1

4

1

2

3

x 3
x 3
x 4
x 4

=

=

-

1

2

 3

12

12

=

=

-

1

1

12

 8

12

 3

12

+

12

12

=

-

Now you solve.

6

1

5

2

2

3

=

=

-

1

6

=

=

-

4

5

1

-

Now you solve.

8

1

3

2

5

6

=

=

-

1

8

=

=

-

6

7

1

Now you solve.

Did you

simplify?

-

1

5

5

6

1

6

Now you solve.

You must

rename.

Did you

simplify?

-

1

5

1

6

5

6

Now you solve.

-

1

9

1

3

5

6

Now you solve.

-

2

4

1

2

5

6

Now you solve.

-

1

9

3

4

1

6

Now you solve.

-

1

4

3

4

5

6

Now you solve.

-

1

4

5

6

3

4

Now you solve.

-

1

4

3

4

Now you solve.

-

1

4

5

6

Now you solve.

-

1

4

3

4

Now you solve.

-

3

6

5

6

2

3

Now you solve.

-

3

6

1

6

2

3

Now you solve.

-

3

8

1

6

1

3

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