Embed Size (px)
Citation preview
Today we will compute a given percent of a whole number.
compute – figure out
Percent means per hundred. It is another way of saying, “out of one hundred.”
Percent
Think of the last time you went to the store to buy an item. Every time you buy something you must pay a sales tax on the product. In order to find out how much sales tax you will pay you must find the percent of a number.
Money & Percents
50% .5050100= =
DecimalFractionPercent
Why is computing a given percent of a whole number important?• You will know exactly how much you will pay
when you buy something.
• You will be prepared for tests like the CST.
• Are there other reasons why?
Find 25% of 78
CD
1. Change the percent to a decimal.
2. Add a zero in front of the decimal
3. Multiply the decimal with the whole number.
4. Place the decimal in the right place.
25 % .0
0. 2 5 x 7 8
0
4
0
2
20
31
7 51
1 9 5 0
+
.
.
19.50
Find 3% of 20
CD
1. Change the percent to a decimal.
2. Add a zero in front of the decimal
3. Multiply the decimal with the whole number.
4. Place the decimal in the right place.
3 % .0
0. 0 3 x 2 0
00000 60
0 0 6 0
+
.
.
0.60
0
Steps1. Change the percent to a decimal. 2. Add a zero in front of the decimal3. Multiply the decimal with the whole
number.4. Place the decimal in the right place
Let’s try them together!
1. Find the 5% of 40
1. Change the percent to a decimal.
2. Add a zero in front of the decimal
3. Multiply the decimal with the whole number.
4. Place the decimal in the right place.
0.05 x40
0 0 0 0 2 0 0+
0 2 0 0 .
2.0
Let’s try them together!
1. Find the 88% of 40
1. Change the percent to a decimal.
2. Add a zero in front of the decimal
3. Multiply the decimal with the whole number.
4. Place the decimal in the right place.
0.88 x40
0 0 0 3 5 2 0+
3 5 2 0 .
35.20
Let’s try them together!
1. Find the 65% of 250
1. Change the percent to a decimal.
2. Add a zero in front of the decimal
3. Multiply the decimal with the whole number.
4. Place the decimal in the right place.
0.65x 2 5 0
0 0 0 3 2 5 0+
1 6 2 5 0 .
162.50
1 3 0 0 0
Lets review
What is percent?
What does compute mean?
What is a decimal?
What is a fraction?
