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Australia
Year 7

4.04 Percentages with technology

Worksheet
Percentage calculations
1

Use a calculator to express the following as percentages:

a

\dfrac{15}{8}

b

\dfrac{581}{700}

c

\dfrac{291}{485}

d

\dfrac{357}{680}

e

44 out of 64

f

899 out of 725

g

5.9 out of 0.32

h

76 out of 91.2

2

Use a calculator to convert the following into decimals:

a

\dfrac{33\,100}{25}\%

b

9.25\%

c

51\% \times 83\%

d

70\% of 617

e

135\% \times 24.6

f

\dfrac{67.2}{24}

g

\dfrac{3}{4} of 65.86

h

72\% \div 3

3

Use a calculator to find the following:

a

23\% of \dfrac{54}{17}

b

91.6\% of 97.3

c

317\% of \dfrac{23.6}{8}

d

126\% of 87.2

e

209\% of \dfrac{29}{22}

f

47.3\% of 1.764

4

Use a calculator to determine x in each of the following:

a

70\% of x is equal to 42.7

b

60\% of x is equal to 39.54

c

60.1\% of x is equal to 24.04

d

46\% of x is equal to 35.88

5

Give some examples of when it might be quicker not to use a calculator in percentage calculations.

Applications
6

A city has a yearly water supply of 27\,000\,000 megalitres. It gets 14\% of this water supply from melted snow. Find the amount of water that comes from melted snow each year.

7

A bag of potatoes weighs 50\text{ kg}. When more potatoes are added, the weight of the bag increases by 35\%.

a

Find the added weight in the bag of potatoes.

b

Find the new weight of the bag of potatoes.

8

Duncan is going to buy a hat that is marked as 25\% off. The original price was \$30.

a

Find the discount amount.

b

Find the discounted price that Duncan will pay for the hat.

9

Ryan scored 60\% on her Maths exam, which was marked out of 110. What was Ryan's actual mark out of 110?

10

The 64 girls at Victoria's party represent 80\% of all the guests.

a

How many guests represent 10\% of all the guests?

b

Find the total number (100\%) of guests at the party.

11
Jane paid \$750 to get a dress made. \$450 of this was for the materials and the rest was for the labour required.
a
Find the percentage of the cost that paid for the materials.
b
Find the percentage of the cost that paid for the labour.
12

A music store advertises 12\% off in all CDs and DVDs. A CD is normally priced at \$18.

a

Find the amount of the discount on this CD.

b

Find the discounted price of the CD.

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Outcomes

ACMNA158

Find percentages of quantities and express one quantity as a percentage of another, with and without digital technologies.

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