Influencing policy (training slides from Fast Track Impact)
Find percents and estimate percent word problems
1. Course 2, Lesson 2-2
Find each number. Round to the nearest tenth if necessary.
1. 165% of 60
2. 233% of 75
3. 48% of 90
4. 20% of $365
5. 80% of 105
6. Tanya earns a perfect score 25% of the time that she performs
her gymnastics routine. If she performs 44 times in a season,
how many times will she NOT receive a perfect score?
6. How to:
• Estimate the percent of a number
• Find percents greater than 100 or less
than 1
Ratios and Proportional Relationships
Course 2, Lesson 2-2
7. 1
Need Another Example?
2
3
4
Step-by-Step Example
1. Jodi has paid 62% of the $500 she owes for her loan.
Estimate 62% of 500.
62% of 500 60% of 500 62% 60%
Multiply.300
So, 62% of 500 is about 300.
9. 1
Need Another Example?
2
3
Step-by-Step Example
2. Marita and four of her friends ordered a pizza that cost $14.72.
She is responsible for 20% of the bill. About how much money
will she need to pay?
Find 10% of $15.00.
10% of $15.00 = 0.1 $15.00
= $1.50 To multiply by 10%, move the
decimal point one place to the left.
Multiply.
20% of $15.00 is 2 times 10% of $15.00.
2 $1.50 = $3.00
So, Marita should pay about $3.00.
10. Answer
Need Another Example?
Melinda calculated that 40% of the coins in
her collection were minted before 1964. If
there are 715 coins in her collection, about
how many of them were minted before 1964?
Sample answer: about 280 coins; 715 ≈ 700
and 10% of 700 = 70 and 70 × 4 = 280
11. Need Another Example?
Step-by-Step Example
3. Estimate 122% of 50.
1
2
3
4
5
120% = 100% + 20%
122% is about 120%.
120% of 50 = 100% of 50 + 20% of 50
100% = 1 and 20% =
= 50 + 10 or 60 Simplify.
So, 122% of 50 is about 60.
= (1 50) + 50
13. 1
Need Another Example?
2
3
4
5
Step-by-Step Example
4. There are 789 seventh grade students at Washington Middle
School. About % of the seventh grade students have traveled
overseas. What is the approximate number of seventh grade
students that have traveled overseas? Explain.
% is one fourth of 1%. 789 is about 800.
1% of 800 = 0.01 800 Write 1% as 0.01.
To multiply by 1%, move the decimal point
two places to the left.
= 8
One fourth of 8 is 8 or 2.
So, about 2 seventh grade students
have traveled overseas.
14. Answer
Need Another Example?
About % of Smithville’s 1,500 adult citizens are
attending the upcoming pop concert. What is the
approximate number of adults attending the
concert?
5 adults; Sample answer:
1% of 1,500 = 0.01 × 1500 = 15, × 15 = 5
15. 1
Need Another Example?
2
3
4
5
Step-by-Step Example
5. Last year, 639 students attended a summer camp.
Of those who attended this year, 0.5% also attended
summer camp last year. About how many students
attended the summer camp two years in a row?
0.5% is half of 1%.
1% of 639 = 0.01 639
6≈
So, 0.5% of 639 is about of 6 or 3.
About 3 students attended summer
camp 2 years in a row.
16. Answer
Need Another Example?
Last weekend, 96,081 people attended a
college football game. About 0.25% of them
were reporters from newspapers, television,
and radio stations. About how many reporters
were at the game?
about 240 reporters: Sample answer:
96,081 ≈ 96,000; 96,000 ×1% = 960
and 0.25 × 960 = × 960 or 240
17. How did what you learned
today help you answer the
HOW can percent help you understand
situations involving money?
Course 2, Lesson 2-2
Ratios and Proportional Relationships
18. How did what you learned
today help you answer the
HOW can percent help you understand
situations involving money?
Course 2, Lesson 2-2
Ratios and Proportional Relationships
Sample answers:
• You can use estimation strategies to estimate the
percent of a dollar amount.
19. Suppose another class
has 120% of the
students that are in our
class. About how many
students are in the
other class?
Ratios and Proportional RelationshipsRatios and Proportional Relationships
Course 2, Lesson 2-2
