Time to conquer our fraction phobias!

A mixed number has a whole number part and a fraction part. Such as

3

25

We connect the whole-number name to the fraction name with the word “and.” This mixed number is read three AND

two fifths.

3 - Whole number part

2/5 - Fraction part

Follow these stepsFollow these steps

1. Find a common denominator.

2. Add or subtract the whole number part.

3. Add or subtract the numerators.

4. Keep the common denominators.

5. Simplify.

1. Common denominator.

2. Add whole number.

3. Add numerators.

4. Keep the common denominators.5. Simplify.

3

+ 2_____________________

Let’s try an Let’s try an example.example.

5 44

Since 4 divided by

4 = 1…

4

1

4

3

2

+ 3

Try a Try a harder harder problem.problem.

RememberRemember to check to see if the smaller

denominator will divide evenly into the larger

denominator.

4 will divide evenly into 8; therefore, 8 is the least common denominator (LCD).

4

1

8

3

22X =

x =

4 x 2 = 8 1 x 2 = 2

The renamed

fraction is 2 eighths2 eighths.

Multiply the fraction partfraction part by another name for 1. The special, select name for

1 is 2 divided by 2.2 divided by 2.

1. Common denominator1. Common denominator

4

1

8

3

8

2

8

3

2

+ 3

2

+ 3

22

X =

x =

52. Add whole number.

3. Add numerators.

4. Keep denominator.

5. Simplify.

4

1

8

38

2

8

3

8

5

Tim and Ken are runners. On Wednesday Tim ran 4 miles and Ken ran 3 miles. How much further did Tim run?

8

7

3

2

Tim and Ken are runners. On Wednesday Tim ran 4 miles and Ken ran 3 miles. How much further did Tim run?

4

- 3_________________________

RememberRemember, when the smaller denominator will not divide

evenly into the larger denominator, you must find the least common multiple for the

denominator.

8

7

3

2

8

7

3

2

Multiples of 8: 0, 8, 16, 2424, 32, …

Multiples of 3: 0, 3, 6, 9, 12, 15, 18, 21, 2424, 27, …

4

- 3_________________________

8

7

3

2

4

- 3

33 =

=

2124

1624

88

7 x 3 = 21 8 x 3 = 24

2 x 8 = 16 3 x 8 =

24

Don’t give up. We are almost there. See you

on the next slide.

x

x

1. Multiply the fraction part by a name for one to get a common denominatorcommon denominator.

8

7

3

2

4

- 3

33 =

=

2124

1624

88

x

x

2. Subtract whole number.1

3. Subtract the numerators.

5

4. Keep the denominators.5. Simplify (if necessary).

24

Yea!

8

7

3

2

Jeffrey is baking brownies. So far he has put in 2 cups of flour and 1 cups of sugar.

What is the total amount of ingredients that he already has in his bowl?

4

1

3

2

2

+ 1

Multiples of 3: 0, 3, 6, 9, 1212, 15, …

Multiples of 4: 0, 4, 8, 1212, 16, …

It gets easier if you practice.4

1

3

2

2

+ 1

33

1 x 3 = 3

4 x 3 = 12= 3

12

44

= 2 x 4 = 8 3 x 4 = 12

812

“I think I can. I think I can. I think I can.”

x

x

1. Multiply the fraction part by a name for one to get a common denominator.common denominator.

4

1

3

2

2

+ 1

33 = 3

12

44

=8

12

x

x

2. Add whole number.

3

3. Add numerators.

11

4. Keep denominator.

125. Simplify.

4

1

3

2

Now for Now for a tricky a tricky

problemproblem..4 -1

Is smaller than ? If so, borrowing may be necessary but perhaps there is an easier way.

3

1

6

5

3

1

6

5

4 - 1

Is smaller than ?

One way to compare fractions is to visualize

them.

<

3

1

6

5

3

1

6

56

5

3

1

is smaller thanis smaller than

4  

 

-1

Don’t worry. Make improper fractions of the mixed numbers.

3

1

6

5

3

1

6

5

4  

-1

3 x 4 + 1=133

= 6 x 1 + 5116

Now follow the steps and shoo your phobias away.

Make improper fractions.Make improper fractions.

4  

-1

=133

= 116

1. Find common denominator.1. Find common denominator.

x

x

22 =

=

266

116

2. There is no whole number.

4  

-1

=133

= 116

x

x

22 =

=

266

116

3. Subtract the numerators.

15

4. Keep the denominators.

6

3

1

6

5

4  

-1

=133

= 116

x

x

22 =

=

266

116

Simplify.

156

156

.÷ 33 = 5

2=

3

1

6

5

2

12

Now it’s time to show what

you know.