Converting Fractions to Converting Fractions to DecimalsDecimals

Adapted from free Powerpoints from the website:http://math.pppst.com/fractions.html

DiscussionDiscussion

• Explain what a fraction is• Explain what a decimal is• Find a decimal that is

equivalent to ¼• What method did you use

to find this?

Problem of the DayProblem of the Day

 

Complete the following

Compare 5/13 to 4/9

Compare 0.384 to 0.4

Fraction is a comparison of two Fraction is a comparison of two numbersnumbers

5/13 to 4/9To compare the

size of each part, the “whole” must be cut into the same size; the denominators must be the same

117

45

9

9

13

5x

117

52

13

13

9

4x

Converting Fractions to Converting Fractions to DecimalsDecimals

To convert a Fraction to a Decimal manually, follow these steps:

Step 1: Find a number you can multiply by the bottom of the fraction to make it 10, or 100, or 1000, or any 1 followed by 0s.

Step 2: Multiply both top and bottom by that number.

Step 3. Then write down just the top number, putting the decimal place in the correct spot (one space from the right for every zero in the bottom number)

Method #1: Converting with Method #1: Converting with ProportionsProportions

Example # 1: Express 3/4 as a Decimal

Step 1: We can multiply 4 by 25 to become 100

Step 2: Multiply top and bottom by 25

3 = 75

4 100

Example # 1 Example # 1 continued….continued….Step 3: Write down 75 with the

decimal place 2 spaces from the right (because 100 has 2 zeros);

Answer = 0.75

Can you explain what we just did?

Try to express ¼ as a decimal using method # 1.

Method #2: Convert by Method #2: Convert by DividingDividing

Example #1: to write 5/8 as a decimal, we need to calculate 5 ÷ 8: 0.625

8 √ 5.000

So = 0.625 as a decimal.

Try this example: write 4/5 as a decimal using division (method #2).

20

48

06.0.58

00.45.80

4 0 0

Lets Practice!!Lets Practice!!

We are going to use this website to fish out some fractions and decimals.

Lets see how well you understand this lesson.

Go to www.iknowthat.comSelect “Math” in the left marginSelect “Fishy Fractions” Select “Fractions and Decimal Match”