3. 𝟑
𝟓
𝟐
𝟏𝟏
𝟒
𝟗
𝟐
𝟕
𝟑
𝟖
60% 28.5%18% 44% 37.5%
2. 𝐑𝐞𝐯𝐢𝐞𝐰 𝐅𝐫𝐨𝐦 𝐓𝐮𝐞𝐬𝐝𝐚𝐲: Write the Percent equivalent
4. What % is
𝟏
𝟏𝟎
of
40?
3.
𝟏
𝟏𝟎
of 500 is what
percent?
What % of 20 is
4?
𝟏
𝟓
of 30 is what
number?𝟏
𝟓
of 50 is what
number?
Warm-Up:
What percent of 30 is
6?
What percent of 50 is
10?
𝟏
𝟏𝟎
of every number is 10%
𝟏
𝟓
of every number is 20%
𝟏
𝟒
of every number is 25%
𝟏
𝟕
of every number is 14%
4. Find 40% using mental math
Find 25% using mental math
1) 20
3) 1201) 5
1) 10 3) 160
3) 110
Find 5% using mental math 1)
30
3) 960
2) 25
2) 48
2) 20
2) 25
Bonus Round: What is 95% of.. 50?
Mental Mathinazation
Please do not say answer until asked so
others may have time to solve. thx.
5. Solving Percent Problems
20 is 50% of 40
(part) (%) (whole)
We will look at this method later, but our first method is
easier because....
20 is 50% of 40 = 20 = .5(40)
This method is…
9. Practice Problems:
% = is
100 of
20 = 30
100 x Cross multiply to find: 20x = 30(100)
20% of what number is 30?
10. x = 6, so our answer is 6%
What percent of 200 is 12?
% = is
100 of
x = 12
100 200
200x = 12(100)
200x = 1200
***Note: The 'of ' is not always the larger number. If the
percent is more than 100, the 'is' will be the larger
number. Be careful when constructing these proportions.
11.
12. 2. Your restaurant has 3 people eating lunch now.
This is 15% of the total seats in the restaurant.
How many people can be seated at one time?
Practice Problems:
19. Mental Math:
Percent of a Number
A. 10% of $1.00 is .1, or
To find 20% of any number, multiply by 2 and move the
decimal one place to the left.
𝟏
𝟏𝟎
(10 cents).
To find 20% of a number, you could multiply a number by what
fraction? B. 20% is what fraction?
.2
20% of 40 is….. 8
The easier way, though, is to multiply a number by the decimal
form of 20%, which is....
To find 10%, simply move the decimal one place to the left.
𝟏
𝟓
20. Mental Math:
Percent of a Number
Find 20% using mental math
Find 15% using mental math
1)
20
3)
42.1
1) 10
4)
120
1)
10
3)
60
3) 60
4) 380
4) 125
2) 25
2) 20
2) 3.5
