Tuesday 9/2 Quick Review

Review Video

Improper and Mixed Fractions

Multiplying With Fractions

I can multiply fractions.

Just Follow These Easy Steps! Multiply the numerators Multiply the

denominators Simplify

Example 1

58

x 34 =

1532

There are no common factors for 15 and 32, so this fraction cannot be simplified.

Example 2

3

4x

29 =

636

This fraction can be reduced. Divide the numerator and denominator by the GCF, which is 6.

= 16

Multiplying by a Whole Number

If you want to multiply a fraction by a whole number, turn your whole number into a fraction by placing a 1 as the denominator.

45

x 201 = 80

5 = 16

Another Example

15 x 161 = 15

615 and 6 have a GCF of 3.

=52

Five halves is improper, so we divide the bottom into the top.

2 52

41

2 12

Simplifying Factors Before you multiply, you can make the problem

simpler. You can find the GCF of any numerator and

denominator. Find a factor that equally divides the top number

and bottom number, divide, and rewrite the problem.

Example 1

57

x 816

In the second fraction, 8 and 16 have a GCF of 8.

8 ÷ 8 = 1 and 16 ÷ 8 = 212

Now, multiply with the simpler numbers. 5 x 1 = 5 and 7 x 2 = 14.5

14

Example 2

2

3x 5

12

The top of the first fraction and the bottom of the second fraction have a common factor. The GCF of 2 and 12 is 2.

2 ÷ 2 = 1, and 12 ÷ 2 = 6.

16

Now, multiply:

518

Homework Time!

TextbookPage 107 1-10

Sponge Wednesday September 3

1) 3) List the steps on how you would multiply a fraction by a fraction.

Multiplying Mixed Numbers

You can NEVER MULTIPLY OR DIVIDE mixed numbers!!!!!

Steps: 1)Make each mixed number an improper fraction. 2)Multiply numerators 3)Multiply denominators 4)SIMPLIFY

Mixed Number Examples….

Examples on your own….

Page 115 1-9 (ODD’s ONLY)

Dividing a Whole Number by a Fraction

What is 3 ÷ ¼ ?

Use your prior knowledge and the illustration above to figure it out. Think, “If I start with 3, how many groups that look like ¼ will I have?”

So, 3 ÷ ¼ = 12.

If you start with 3, you will have 12 groups of 1/4 .

1 2

3 4

5 6

7 11

10

12

9

8

Dividing a Whole Number by a Fraction

Can you see how you could manipulate the fractions to get an answer of 12?

Dividing a Whole Number by a Fraction

So, 5 ÷ 1/3 = 15.

If you start with 5, you will have 15 groups of 1/3 .

What is 5 ÷ 1/3?

Can you see how you could manipulate the fractions to get an answer of 15?

Steps….

1) Make the whole number a fraction by putting a 1 in the denominator

2) Keep the first fraction the same

3) Change the division sign to multiplication

4) Flip (take the reciprocal) of the second fraction

5) Now you use Multiplication Steps

Examples:

Homework Page 139 2-12 (EVEN’s ONLY)

Sponge Thursday September 4

Homework Check

Vocabulary: Reciprocal

When you flip the second fraction, you are writing that fraction’s reciprocal.

35

53

To Divide Fractions by Fractions: Rewrite the first fraction. Change the division sign to a multiplication

sign. Flip the second fraction upside down. Multiply.

Example 1

1

3÷ 1

2Rewrite:

13

x 21 = 2

3

Example 2

4

5÷

4

9Rewrite:

45

x 94

11 = 9

5=1 4

5

Review Example 3

12 ÷ 351

Rewrite:

121

x 53

41

=20

1= 20

Review Example 4

16

÷ 21

Rewrite:

16

x 12

=112

Re-cap of today’s lesson

Dividing Fractions Re-cap

Homework Page 153

18-21; 23-26

Friday Sponge September 5

Explain the steps you need to complete to divide fractions by fractions.

Divide Mixed Numbers

Check Homework

Change any mixed numbers into improper fractions.

Change any whole numbers into improper fractions by putting 1 under the whole number.

KEEP – CHANGE - FLIP.

Multiply numerators and denominators

Simplify

Example 1

1 19 ÷ 6 2

3

÷10

9203

x10

9320

123

1=

16

More Practice…

Example 2:

6 ÷ 3 ½

Example 3:

1 ½ ÷ 3 ¾

On your own….

Textbook Page 159 (1-3)

Quiz –Take out a sheet of paper and write your name on it

Homework:Review videos on web blog from this week’s

lessons