ions, decimals and percentages
Getting started
1) Write these fractions in 2) Write these fractions as decima
their simplest form.
Fractions, decimals and percentages
1) Write down as a fraction, a
percentage and a decimal the
part of shape that is coloured
pink.
2) The area of shape is 45 cm2.
Work out the area that is shaded
pink.
and percentages
te these percentages as decimals and as
fractions.
20%
a. c.8%
9% d.23%
10.1 Fractions, decimals and
percentages
Write these fractions as percentages.
1 3
e. 4 i. 4
3 4
f. 20 j. 20
5 7
25 25
g. k.
10.1 Fractions, decimals and percentages
Write these decimal numbers as fractions and percentages.
l. 0.6
m 0.08
n. 0.375
10.1 Fractions, decimals and
percentages
=
Fractions Decimals Percentages
¾
0.25
35%
0.12
5
3_
50
10.2 Percentages large and small
Arun has $20.
He gives $5 to Marcus and $13 to Sofia.
What percentage does each person
get? What percentage is left?
10.2 Percentages large and small
Question 13.
Marcus has 500 g of flour. He uses 200 g to bake
bread and 120 g to make biscuits.
Work out the percentage of the flour:
a. he uses for bread
b. he uses for
biscuits
c. he does not use
10.2 Percentages large and small
Question 14.
Sofia works for 40 hours in a week. She spends 25
hours in her office, 8 hours in the factory and the rest
of the time in a workshop.
Work out the percentage of the time that she spends:
a. in her office workshop
b. in the
factory
c. in a
10.2 Percentages large and small
Question 15.
Zara earns
$250.
She pays $95 in tax and pays a bill of $65.
Work out the percentage of her money:
a. she pays in
tax
b. she has left after both
payments
10.2 Percentages large and small
Question 2. Write these percentages as decimals and
as fractions. Write each fraction in its simplest form.
(a) 7.5% (d) 47.5%
(b) 62.5% (e) 32.5%
(c) 1.5%
10.2 Percentages large and small
Question 4. Write these percentages as fractions in
their simplest form.
(a) 2% (d) 0.8%
(b) 0.2% (e) 7%
(c) 8% (f) 0.7%
10.2 Percentages large and small
Questions 5-6. Work out:
(a) 1.5% of 600 kilograms
(b) 2.2% of 600 kilograms
(c) 0.3% of 7000 metres
(d) 0.5% of 7000 metres
10.2 Percentages large and small
Questions 9. Write each of these mixed numbers as
a percentage.
10.2 Percentages large and small
Questions 10
(a) Write these mixed fractions as percentages:
10.2b Percentage changeQuestion 16.
An airline ticket costs $40.
The price is increased by
200%.
a. Work out:
i. the increase
ii. the price after the increase
b. Find the number to complete this
sentence: The new price is times the
original price
10.2b Percentage change
Question 17.
The mass of a puppy is 5 kg.
As it grows, the mass increases by 300%
a. Work out:
i. the increase in mass
ii. the new mass
b. Find the number to complete this
sentence: The new
__ mass is _ times the
original mass.
10.2b Percentage change
Question 18.
(a) The cost of a car increases by 5%. What
percentage of the original price is the new
price?
(b) The cost of petrol increases by 80%. What
percentage of the original price is the new
price?
â
What is 170% of $60?
What percentage of $50 is $40?
What percentage of $40 is $50?
What percentage of $60 is $102?
12.2 Sharing in a ratio
Recap
Simplify the ratio
a) 35 minutes : 1 hour
b) 8 days : 2 weeks
12.2 Sharing in a ratio
Example
1) Share $9000 between Sally and Bob in the
ratio 2 : 1.
2) Raine and Abella share an electricity bill in
the ratio 5:4.
The electricity bill is $72.
How much does each of them pay?
12.2 Sharing in a ratio
STEP1: Add the total parts STEP2: Divide the amount STEP3: Multiply by
by the total parts the ratio
Share these amounts between Dong and Chul in the ratios given:
1) $32 in the ratio 2) $45 in the ratio
3:1 2:3
3) $49 in the ratio 4) $84 in the ratio
2:5 3:4
5) A tin of biscuit contains shortbread and
choc-chip biscuits in the ratio 2:3. The tin
contains 40 biscuits.
How many shortbread biscuits are
there in the tin?
6) A school choir is made up of girls
and boys in the ratio 4:3. There are
35 students in the choir together.
(a) How many of the students are
boys?
(b) What fraction of the students are
boy
