FRACTION REVIEW

34

FRACTION - a number that shows parts or pieces of a whole

denominator

numerator

74

IMPROPER FRACTION - when the number on top is bigger than the number on the bottom.

34

MIXED NUMBER - a number that shows wholes and fractions

1

Adding Fractions

34

25+

Step 1: Find a common denominator

Hmmm…

Adding Fractions

34

25+

Step 1: Find a common denominator

The LCM of

4 and 5 is 20.

Step 2: Find equivalent fractions with the common denominator

Adding Fractions

34

25+

Step 1: Find a common denominator

Step 2: Find equivalent fractions with the common denominator

5 x x 4

The LCM of

4 and 5 is 20.

Adding Fractions

34

25+

Step 1: Find a common denominator

What you do to the bottom

you have to do to the top.

Step 2: Find equivalent fractions with the common denominator

5 x

5 x

x 4

x 4

Adding Fractions

1520

820+

Step 1: Find a common denominator

Step 2: Find equivalent fractions with the common denominator

Step 3: Add the numerators. Keep the same denominator.

What you do to the bottom

you have to do to the top.

Adding Fractions

1520

820+

Step 1: Find a common denominator

15 + 8 = 23

Step 2: Find equivalent fractions with the common denominator

Step 3: Add the numerators. Keep the same denominator.

Adding Fractions

1520

820+

Step 1: Find a common denominator

Step 2: Find equivalent fractions with the common denominator

Step 3: Add the numerators. Keep the same denominator.

= 2320

Adding Fractions

Step 1: Find a common denominator

Change impropers to

mixed #s

Step 2: Find equivalent fractions with the common denominator

Step 3: Add the numerators. Keep the same denominator.

Step 4: Simplify if necessary

1520

820+ = 23

20

Adding Fractions

Step 1: Find a common denominator

Step 2: Find equivalent fractions with the common denominator

Step 3: Add the numerators. Keep the same denominator.

Step 4: Simplify if necessary

1520

820+ = 23

20 = 3201

20 can go into 23 1 time.

There is a remainder of 3.

Subtracting Fractionsis almost like adding.

Subtracting Fractions

Step 1: Find a common denominator

12

16 - Hmmm…

Subtracting Fractions

Step 1: Find a common denominator

Step 2: Find equivalent fractions with the common denominator

12

16 - The LCM for

2 and 6 is 12

Subtracting Fractions

Step 1: Find a common denominator

Step 2: Find equivalent fractions with the common denominator

6 12

212- The LCM for

2 and 6 is 12

Step 3: Subtract the numerators. Keep the same denominator.

Subtracting Fractions

Step 1: Find a common denominator

Step 2: Find equivalent fractions with the common denominator

6 - 2 = 4

Step 3: Subtract the numerators. Keep the same denominator.

= 412

6 12

212-

Subtracting Fractions

Step 1: Find a common denominator

Step 2: Find equivalent fractions with the common denominator

4 and 12 share a common factor of 4

Step 3: Subtract the numerators. Keep the same denominator.

Step 4: Simplify if necessary

//

4

4

= 13= 4

126 2

12-12

Multiplying Fractions is way easier than adding and

subtracting.

Multiplying Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

Ummm…

I don’t know.

=4 6x73

Multiplying Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

=4 6x73 Oh good!

Multiplying Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

Oh good!

=4 6x73

Step 1: Multiply the numerators.

Multiplying Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

4 x 3 = 12

=4 6x73

Step 1: Multiply the numerators.

Step 2: Multiply the denominators

12

Multiplying Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

7 x 6 = 42

=4 6x73

Step 1: Multiply the numerators.

Step 2: Multiply the denominators

1242

Step 3: Simplify if necessary

Multiplying Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

The GCF for 12 and 42 is 6

=4 6x73

Step 1: Multiply the numerators.

Step 2: Multiply the denominators

1242

Step 3: Simplify if necessary

6

6// 2

7=

Dividing Fractions is easy if you remember one

little thing.

Dividing Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

Do I need a common

denominator?13/22

Step 1: Find the reciprocal of the second fraction

Dividing Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

FLIP THE SECOND ONE!1

3/22

Step 1: Find the reciprocal of the second fraction

Dividing Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

12/23

Step 1: Find the reciprocal of the second fraction

Step 2: Change division to multiplication

FLIP THE SECOND ONE!

Dividing Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

/ to X 12/23

Step 1: Find the reciprocal of the second fraction

Step 2: Change division to multiplication

Dividing Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

1223

Step 1: Find the reciprocal of the second fraction

Step 2: Change division to multiplication

x

Step 3: Multiply and simplify if necessary

/ to X

Dividing Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

1 x 3

and

2 x 2 1223

Step 1: Find the reciprocal of the second fraction

Step 2: Change division to multiplication

x

Step 3: Multiply and simplify if necessary

= 34

Dividing Fractions

YOU DO NOT NEED A COMMON DENOMINATOR

EASY!!! 1223

Step 1: Find the reciprocal of the second fraction

Step 2: Change division to multiplication

x

Step 3: Multiply and simplify if necessary

= 34

Special Situations

• Adding and subtracting mixed numbers: just add or subtract fractions, then wholes.

• Subtracting mixed numbers when the first fraction part is smaller than the second: change to improper fractions.

• Multiplying and dividing mixed numbers and wholes: change to improper fractions

Get into partner groups

Adding Fractions

Subtracting Fractions

Multiplying Fractions

Dividing Fractions

Multiplying or Dividingmixed numbers