Transcript Percent and Estimation

Click the mouse button or press the
Space Bar to display the answers.
Objective
Estimate percents by using fractions
and decimals
Vocabulary
None
Example 1 Use Fractions to Estimate
Example 2 Use Fractions to Estimate
Example 3 Estimate by Using 10%
Example 4 Percents Greater Than 100 or Less Than 1
Example 5 Percents Greater Than 100 or Less Than 1
Example 6 Estimate Percent to Solve a Problem
Write the problem
Estimate 61% of 407
61% of 407
60%  400
6  4
.
24000
Answer:  240
Remember: When directions
say to “estimate” the exact
answer will be wrong
Round 61% to an easy number
“of” refers to multiplication
Round 407 to an easy number
Multiply non-zero numbers
Bring down zeros
Remove % sign by dividing
by 100 (move decimal 2
places to the left)
1/6
Estimate 28% of 92.
Answer: 27
1/6
Write the problem
Estimate 18% of 296
18% of 296
20%  300
23
.
6 000
Answer:  60
Remember: When directions
say to “estimate” the exact
answer will be wrong
Round 18% to an easy number
“of” refers to multiplication
Round 296 to an easy number
Multiply non-zero numbers
Bring down zeros
Remove % sign by dividing
by 100 (move decimal 2
places to the left)
2/6
Estimate 71% of 198.
Answer:  140
2/6
Write the problem
Estimate 59% of 500
59% of 500
60%  500
65
30000
.
Answer:  300
Remember: When directions
say to “estimate” the exact
answer will be wrong
Round 59% to an easy number
“of” refers to multiplication
500 is already an easy number
Multiply non-zero numbers
Bring down zeros
Remove % sign by dividing
by 100 (move decimal 2
places to the left)
3/6
Estimate 39% of 700
Answer:  280
3/6
Write the problem
Estimate 173% of 60
173% of 60
170%  60
17  6
102.00
Answer:  102
Remember: When directions
say to “estimate” the exact
answer will be wrong
Round 173% to an easy
number
“of” refers to multiplication
60 is already an easy number
Multiply non-zero numbers
Bring down zeros
Remove % sign by dividing
by 100 (move decimal 2
places to the left)
4/6
Estimate 142% of 80.
Answer:  112
4/6
Write the problem
Remember: When directions
say to “estimate” the exact
answer will be wrong
of 898
Keep
 900
 9
3 00
as is
“of” refers to multiplication
Round 898 to number
compatible with 3 the
denominator
Multiply non-zero numbers
Bring down zeros
5/6
of 898
Remove % sign by dividing
by 100 (move decimal 2
places to the left)
 900
 9
.
300
Answer:  3
5/6
Answer:  2
5/6
GAME ATTENDANCE Last season 96,081 people were in
attendance at a college football game. About 0.25% of
those were reporters from newspapers and television and
radio stations. About how many media people were
present?
Write the problem
0.25% of 96,081
Round 0.25% to an easy
number
0.3%  96,000
“of” refers to multiplication
Round 96,081 to an easy
number
6/6
GAME ATTENDANCE Last season 96,081 people were in
attendance at a college football game. About 0.25% of
those were reporters from newspapers and television and
radio stations. About how many media people were
present?
Multiply non-zero numbers
0.25% of 96,081
Bring down zeros
0.3%  96,000
Remove % sign by dividing
by 100 (move decimal 2
places to the left)
3  96
288.000
Answer: 288 people
Remove decimal in 0.3 by
moving the decimal 1 more
place to left
Add dimensional analysis
6/6
*
CONCERT The attendance at a popular outdoor
concert was recorded as 6,973. Of those attending,
0.5% were security personnel. About how many
security people were present?
Answer:  35
6/6
Assignment
Lesson 8:1 Percent and Estimation
15 - 32 All