Fractions

DECIMALS

Adding and Subtraction Decimals

Add: 28.5 + 44.47 + 3075.6		Subtract : 380.53 - 75
	Step 1: Line up the decimal points.
	Step 2: Then add or subtract.

Multiplying Decimals

Multiply 1.89 x 5.03 = ___

	Step 1: Multiply the decimals as you would do with whole
	Step 2: Then count the number of spaces of each factor being multiplied. Decimal places are the number of spaces to the right of the decimal point , There is 2 in the top factor and two in the bottom factor, so the decimal is placed 4 spaces from the right.
	Step 3: Show the total number of places in your answer.

Dividing a Decimal by a Whole Number

Example:

Place the decimal point directly above its position in the problem. Then divide the same way as you divide whole numbers.

Dividing a Decimal by a Decimal Number

Example: 4.374 ÷ .03 = __

Move the decimal point of the divisor ( outside the bracket ) as far right as you can go. Then move the decimal point in the dividend (inside the bracket) the same number of places as the divisor.

Place the decimal point directly above its position in the problem. Then divide the same way as divide whole numbers.

Practice:

Answers:

PERCENTS

Percents are used to describe a part of something. Percents are used to figure out sales or the amount of interest someone will pay on a
loan. When converting a percent to its fraction form , it will always have a denominator of 100.

Changing Decimals to Percents or Percents to Decimals
The important key is where to move the decimal point. If changing from decimal to a percent , you would need to move the decimal
point two places to the right and add the percent sign .

Example:


To change from percent to decimal, need to move the decimal point two places to the left and drop the percent sign.

Example:


Converting Fraction to Percent Form
Divide the bottom number of the fraction into the top number and move the point two places to the right.

Example:

-or-

Multiply the fraction by 100%
Example:

Percent to Fraction
Example: 85%

Write the percent as a fraction with 100 as the denominator . Then reduce the fraction to lowest terms .

Percent of a Number

Finding What Percent One Number Is of Another
There are key words to remember that will help you solve the problem it is asking you.
The word ‘of’ in the sentence means to multiply.
The word ‘is‘ means it is equal to.

Example:

The variable ‘a’ is being multiplied by 45. Need to divide by 45.

Finding a Number When a Percent of It is Given

Example:

Change the percent to fraction form.

Need to multiply both sides of the equation by 5.

Practice:
Write the following in percent form.

6. What is 11% of $3,000?

7. 60 is what percent of 12,000?

8. 28 is 40 % of what number?

Answers: