TOPIC
17
Strand:
Strand unit:
514
515
516
1.
2.
3.
4.
5.
Develop an understanding of simple percentages and relate them to fractions and
decimals.
Compare and order fractions and decimals.
Solve problems involving operations with whole numbers, fractions, decimals and
simple percentages.
Converting fractions to decimals and decimals to fractions.
Calculating a fraction or decimal fraction of a set.
Calculating a number given a fraction or decimal fraction of the number.
Expressing a number as a fraction of another number.
Solving problems involving fractions and decimals.
1. Applying and problem-solving: Applying the concept of percentage to a variety of contexts,
apply a variety of concepts from fractions, decimals and percentages to solve problems.
2. Integrating and connecting: Connect informally held ideas on percentages with formal
mathematical ideas and processes, recognise the use of percentages in the environment,
represent ideas on fractions, decimals and percentages using diagrams and number lines.
3. Reasoning: Search for and investigate patterns between fractions, decimals and percentages.
4. Implementing: Use mental strategies to convert from fractions and decimals to percentages.
Newspapers
Fractions, decimals, percent, percentage, hundredths, equivalent, decimal point,
mixed numbers, convert
1. Revise fraction and decimal equivalents.
2. Children will have some experience of percentages from their environment. Brainstorm the use
of percentages in the environment, e.g. sales, exams.
3. To calculate a percentage of a number, students will need to be reminded to convert the
percentage to a fraction first.
Fans:
What percentage is 25 out of 50, 30 out 60, 10 out of 100 , 60 out of 120?
How many hours in 60 minutes? 120 minutes? 180 minutes? 240 minutes? 300 minutes?
Show the pattern.
Target board 12:
How many hours and minutes in each number?
Sound of number.
1. Collect examples of the occurrence of percentages in the environment, e.g. shop windows,
catalogues, flyers and in newspapers.
2. Get children to convert old test results into percentages.
3. Examine the use of percentages by banks, building societies and credit unions. Which institution
is cheapest for a student loan of €1,000? Which institution offers the best interest rate on a
deposit of €1,000?
4. Conduct surveys using 100 children in the school. Represent the results in bar charts using
percentages.
5. Explore the meaning of the word ‘cent’ (from the Latin word ‘centum’). What other words begin
with ‘cent’ and what is their meaning?
Students will need the following colours to complete this task: red, green, blue, yellow and
black.
In box 1:
Colour 14 red and 0·35 green. What fraction is left? Colour it yellow.
In box 2:
Colour 55 blue and 0·3 black. What decimal fraction is left? Colour it red.
In box 3:
3
red and 0·55 yellow. What decimal fraction is left? Colour it blue.
Colour 10
Lower attainers:
Extra practice converting from fractions and decimals to percentages.
Higher attainers:
1. Extra practice converting from fractions and decimals to percentages.
2. Word problems including fractions, decimals and percentages.
3. Activities B and D on page 112 will provide a stretch for high attainers.
Topic
Topic
17
17
1. (a)
(b)
(c)
1
4
30%
1
5
1. Change each decimal to a percent and to a fraction or mixed number in its lowest terms.
(a) 0.4
(b) 0.96
3
10
(c) 0.05
0.09
25%
0.45
32%
What % is black?
What % is unshaded?
0.24
(f) 0.9
(h) 1.55
2. Change each percentage to a decimal.
(b) 34%
(a) 96%
What % is unshaded?
(c) 50%
2. Write each fraction as a decimal and a percentage.
(a)
1
2
(b)
1
4
(c)
1
5
(d)
2
5
(e)
3
4
(f)
3
10
(g)
4
5
(h)
61
100
(b) 80%
(c) 12%
(d) 50%
(e) 75%
(f) 90%
(g) 35%
(h) 5%
(d) 62%
(e) 3%
(f) 100%
(g) 67 12 %
(h) 12 12 %
3. Calculate the following.
(a) 35% of ___ = 14
(c)
3. Write each percentage as a decimal and as a fraction in its lowest terms.
(a) 25%
(d) 0.83
(e) 0.25
(g) 1.1
2
3
of ___ = 12
(b)
5
8
(d)
3
20
of ___ = 15
(f)
13
20
of ___ = 39
of ___ = 10
(e) 95% of ___ = 95
(g) 0.25 of ___ = 4
(h) 0.75 of ___ = 18
4. (a) 0.75 of the apples in a box are red. What percentage are green?
(b) In a survey 0.22 preferred water to milk. What percentage of people preferred milk?
(c) Jamie scored 65 out of 100 in his maths test. What percentage did he get?
(d) 0.55 of the animals on a farm are sheep,
1
5
are cattle and the rest are horses. What percentage
of the animals are horses?
4. Write each decimal as a percent and as a fraction in its lowest terms.
(a) 0.8
(b) 0.25
(c) 0.05
(d) 0.1
Name: _______________________________________
she spend?
(g) Which amount is greater, 70% of €10 or
Date: ___________________
4
5
of €9 and by how much?
(h) A large pizza had 16 slices. If 75% of the pizza was eaten. How many slices would be left?
Name: _______________________________________
Date: ___________________
© Folens Photocopiables
(f) 0.75
(h) 0.02
(f) Jane spent 0.35 of her money in one shop and 25% in another. What fraction of her money did
© Folens Photocopiables
(e) 0.45
(g) 0.3
(e) A pizza was divided equally among 5 children. What percentage of the pizza did they each get?
144
Fractions: Converting decimals and percentages to fractions and vice versa
Data: The relationship between chance and percentages
Number: Operations – Operations involving division and multiplication
English: Etymology of ‘cent’, describing social events using percentages
Geography: Population distribution and percentages
At the end of this chapter students should be able to convert from fractions and decimals to
percentages. They should also be able to find a fraction, decimal or percentage of a number.
Children should be encouraged to use percentages in everyday situations such as: sharing and
dividing food, dividing quantities of money, reading sale signs in the media and in shops and
understanding the use of percentages by banks, building societies and credit unions.
Notes
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