The ideas in this lesson are taken from Math Mammoth Percent book.
What Percentage...? / How many percent...?
The concepts and ideas of this lesson are also explained in this video:
What percentage of the height of a 15-ft tree is a 3-ft sapling? |
A choir has 22 women and 18 men. Find what percentage of the choir’s members are men. |
One pair of jeans costs $25 and another costs $28. How many percent is the price of cheaper jeans of the price of the more expensive jeans? |
Look carefully at the questions above. Notice that the problems don’t tell you the percentage; in other words, there is no number in the problem written as x%. Instead, they ask you to find it!
Questions with “What percentage ... ?” or "How many percent ... ?" |
Asking “What percentage?” or "How many percent?" is the same as asking “How many hundredth parts?” We can solve these questions in a two-part process: 1. First find out
the part that is being asked for as a
fraction. 2. Convert that fraction to a decimal. Then
you can easily convert |
Example 1. A choir has 22 women and 18 men. Find what percentage of the choir’s members are men. 1. Find out what
part (fraction)
of the choir’s members are men. 2. Write 9/20 as a percent. Use
equivalent fractions: |
Example 2. One pair of jeans costs $25 and the other costs $28.
1. Write what part the
cheaper price is of the more expensive price. 2. Write 25/28 as a percentage. A
calculator gives 25/28 = 0.8928... |
1. a. What percentage of a 15-ft tree is a little 3-ft sapling?
b. How many percent is $12 of $16?
2. Find how many percent the smaller object’s height is of the taller object’s height.
a. |
b. |
c. [available in the book] |
3. A 2-year old child measures 32
inches tall and weighs 24 pounds.
A 10-year old child measures 52 inches tall and weighs 96 pounds.
a. How many percent is the smaller child’s
age of
the older child’s age?
b. How many percent is the smaller child’s
height
of the older child’s height?
c. [available in the book]
4. Write the percentages into the sectors in the circle graphs. Think of fractions!
a. | b. [available in the book | c. [available in the book] |
5. The circle graph at the right gives the angle measure
of each sector of the circle. Find what percentage each
sector is of the whole circle, and write the percentage
in the sector. Remember, the whole circle is 360°.
6. [available in the book]
Draw a
circle graph to represent |
The ideas in this lesson are taken from Math Mammoth Percent book.
See also these lessons:
Percent - the concept and how to change fractions to percents
Percent of a number using mental math
How to find a percentage of a number using decimals
Generate free percent worksheets:
Percent/decimal worksheetsPercent of number (simple)
Percentages/percent word problems