Fractions and Decimals
Adding and Subtraction Decimals
Add: 28.5 + 44.47 + 3075.6
|Step 1: Line up the decimal points.|
|Step 2: Then add or subtract.|
Subtract: 380.53 - 75
Multiply 1.89 x 5.03 = ___
Step 1: Multiply the decimals as you would do with
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
Place the decimal point directly above its position in the
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.
Percents are used to describe a part of something.
Percents are used to figure out sales or the amount of interest someone will pay
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.
0.35 = 35%
0.8 = 80%
To change from percent to decimal, need to move the
decimal point two places to the left and drop the percent sign.
30% = .3
0.9% = .009
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.
Multiply the fraction by 100%
Percent to Fraction
Write the percent as a fraction with 100 as the
reduce the fraction to lowest terms.
Percent of a Number
|1) What is 25% of $6,500.||-or-||2) Change the percent to a fraction|
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.
Finding a Number When a Percent of It is Given
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?