Vocabulary
"a measure of a quantity's reduction relative to its original value, expressed as a percentage"
percent decrease
20% of 40
8
Shirt Cost: $30
Sales Tax: 6%
$31.80
Maria measured a pencil and thought it was 18 cm long.
The actual length of the pencil is 20 cm.
What is Maria’s percent error?
10%
1/8 as a decimal
0.125
"measures how much a quantity has grown compared to its starting value, expressed as a percentage"
percent increase
110% of 50
55
Meal Cost: $65
Tip: 15%
$74.75
A thermometer shows the temperature as 72°F, but the actual temperature is 75°F.
What is the percent error in the thermometer’s reading?
4%
7/11 as a decimal
0.63 repeating
"difference divided by desired times 100"
percent error
60% decrease from 30
12
Food Cost: $50
Coupon: 10% off
$45
A teacher predicts 145 students will come to a school assembly.
Only 132 students show up.
What is the percent error in the prediction?
Round to the nearest whole
9%
18/20 as a decimal
.9
"a decimal number where one or more digits in the decimal part repeat infinitely in a pattern"
repeating decimal
Input: 20
Output: 29
What is the percent of change?
increase of 45%
Meal Cost: $60
Tax: 6.5%
Tip: 10%
$70.29
A coach estimates a runner’s top speed is 18.5 mph, but electronic timing shows the speed is actually 20 mph.
Find the percent error.
7.5%
6/7 as a decimal
0.8571
"a decimal number that ends after a limited number of digits"
terminating decimal
Percent of Change: 60%
Output: 150
What is the input?
90
Meal Cost: $75
Coupon: 40% off
Tax: 6%
Tip: 20%
$57.24
A student estimates that a container holds 3.2 liters of water.
The actual capacity is 3.8 liters.
What is the percent error?
Round to the nearest whole
16%
3/17 as a decimal
0.1764