Week 9 - Percent

Question 1

Define a percentage

Answer 1

A percent or percentage is a fraction
expressed as a number out of 100
followed by the % symbol.

Question 2

Percentages are fractions written as a part of….

Answer 2

one hundred (100)

so 1/2 = 0.5 = 50/100 or 50%

Question 3

Why are percentages useful?

4 points

Answer 3

Percentages allow quick and easy comparison of rational numbers.

The relative sizes of 2/3 and 7/10 are expressed more clearly as 67% and 70%.

To convert a fraction to a decimal:
numerator, denominator

To convert a decimal to a percentage:
decimal x 100

Question 4

To convert a decimal to a percentage

Answer 4

Decimal x 100

Question 5

To convert a percentage to a decimal

Answer 5

Divide by 100

Question 6

Convert fraction to a decimal

Answer 6

Divide the top number by the bottom number

Question 7

Convert decimal to a fraction

Answer 7

Place decimal number over its place value

E.g. 0.6, the 6 is in the tenths place, so we get 6/10

Question 8

Convert fraction to percentage

Answer 8

Divide numerator (top) by the denominator (bottom) then multiply by 100

Question 9

Part of the whole equation =

Example

Answer 9

Percent x whole

E.g. 70% of $60 = $42
70/100 x 60 = 42

Question 10

Percentage question example

Devon has $2500 owing on his credit card. He pays 15% interest per month on what he owes.

How much will Devon pay in interest this month if he does not pay anything off his card?

Answer 10

Amount = percent x whole

= 15/100 x 2500 = $375

Question 11

Percentage question example

Joshua sat his driving test. out of 20 he got 17 correct. What percentage is that?

Answer 11

Part/Whole x 100

= 17/20 x 100 = 85%

Question 12

Percentage question example (Find the whole given the percentage and the part)

Example: Jim paid $400 off the balance of his credit card account, which represented 80% of the balance. What was the original balance?

Answer 12

80% of Balance = 400
0.8 x balance = 400
Balance = 400/0.8
= $500

Question 13

Percentage mental strategies

Answer 13

Identify the components and what is missing
- Whole
- Part
- Percent

How would you find 10%, 25%, 50%

Linking percentage to fraction may assist

Question 14

Percentage example

A horse eats about 60% of its own body weight each month. This horse weighs 550 kilograms

Answer 14

60%
550
Missing the part

0.6 x 550 = 330kg

Question 15

Percentage example

There are 250 cows in the herd. They give birth to 400 calves. What is the calving percentage?

Answer 15

Whole: 400
Part: 250

(400/250) x 100 = 1.6 = 160%

Question 16

Percentage example

Calculate using percentages

33% of the teachers in a school are 4 year trained. There are 45 teachers in the school. How many are 4 year trains

Answer 16

33% of 45
0.33 x 45 = 14.85 or 15