COURSEBOOK 2nd Edition6B

Charlotte Collars • Koay Phong Lee • Lee Ngan Hoe • Ong Bee Leng • Tan Cheow Seng (Cert. Ed.) (Ph.D.) (Ph.D.) (B.Sc., Dip. Ed.) (Cert. Ed.)

•APPROVE

DBY

MINISTRY OF EDUCATION

•

for use from 2009–2

017

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Chapter OpenersEncourages active pupil participation in learning.

Friends of Shaping MathsThe themes in the coursebook revolve around Aini, Bala, Caili and David. The characters help to stimulate pupils’ interest and heighten their involvement in the learning process.

PREFACEShaping Maths is an instructional package written according to the latest Primary Mathematics Syllabus provided by the Ministry of Education, Singapore. The package is designed to meet the learning needs of pupils from Primary 1 to 6. For Primary 6, the package consists of two coursebooks, four activity books and a teacher’s resource pack.

Approach

The Primary 6 (2nd Edition) package is designed to provide continuity in the way pupils experience Mathematics through the lower primary packages. Wherever possible, familiar everyday situations are used to introduce new topics so that pupils will be able to relate the application of new concepts learnt with their daily lives. Through its concrete-pictorial-abstract approach in implementing the spiral curriculum, this package seeks to promote pupil engagement and enhance the learning process.

Continuing research in education has resulted in the introduction of new features in the second edition. Through these features, educators are further equipped with various strategies in addressing teaching and pupils’ learning needs. These features also include more open-ended questions so as to encourage exploration and in-depth thinking among pupils. Thus, mathematically inquisitive learners are born!

Features

Recall Activity Marker Emphasises the importance of establishing connections in learning mathematics. The marker directs pupils to a diagnostic exercise, Recall, in the activity book.

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My NotesHelps pupils to consolidate and recall their learning and commit to memory some key ideas.

Review Helps pupils to consolidate their learning.

Question Classifi cation – pre-requisite skills

– reinforcement of current concepts

– higher-order thinking skills

Helps teachers to spend their time more effectively by using the appropriate questions to get pupils to master the necessary skills.

Use of Calculator Inculcates the appropriate use of calculators without compromising basic computational skills through:• introducing pupils to and providing guidance

on the use of calculators,• encouraging pupils to exercise judgement

where the use of calculators is optional, thus appreciating the power of mental computation versus calculator-based computation,

• exposing pupils to investigations involving tedious computation, so that they can appreciate the calculator as a learning tool.

SummaryA one-page summary helps pupils to consolidate their learning for each semester. It also serves as a quick revision guide for pupils, especially when preparing for semestral assessments.

Fun With Maths Engages pupils in interactive mathematical activities that encourage exploration, discovery and active thinking.

π

ππ

π

π

π

π

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★ vi ★

1 Circles 2 • Radius and Diameter 3 • Circumference 7 • Area 14 • More Problems on Circles 21

2 Pie Charts 26 • Reading Pie Charts 27

Review A 34

Revision A 45

3 Volume 54 • Cubes and Cuboids 56 • Solving Word Problems 61

4 Triangles and Four-sided Figures 70

Review B 80

Revision B 91

CONTENTS

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★ vii ★

5 More Challenging Problems (1) 100 • Whole Numbers and Decimals 100 • Fractions 109

6 More Challenging Problems (2) 117 • Ratio 117 • Speed 122 • Percentage 124

7 More Challenging Problems (3) 127 • Average 127 • Graphs 132 • Geometry 136 • Measurement 140

My Summary 147

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Circles1

AB 6B Part 1, Recall 1

Geometric fi gures are often used to enhance the beauty of building designs. In the photograph above, the ceiling is composed of several circles that share the same centre.

2

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A Bfold

unfold

Radius and Diameter

Trace a 50¢ coin on a piece of paper. Cut out the tracing of the paper circle. Then, fold the paper circle in half as shown. Draw and name the fold line as AB.

Compare the diameter AB and the radius OC.What do you notice?

The line AB divides the circle into equal halves. AB is a diameter of the circle. How long is the diameter of the 50¢ coin?

Fold the paper circle in half in another way to obtain another diameter of the circle. The two diameters meet at a point. This point is the centre of the circle. Name the centre O.

Draw a straight line from the centre O to any point C on the edge of the circle. The line OC is the radius of the circle. How long is the radius of the 50¢ coin?

A B

anotherdiameter

diameter

O

A B

anotherdiameter

diameter

O

radius

C

3

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The diameters of a circle pass through the centre of the circle. The diameter of a circle is twice its radius.Diameter = 2 � RadiusRadius = Diameter � 2

1 Measure the diameter of each circle. Calculate the radius.

diameter

O

A

B

O

C

O

4

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The circles to the right are not drawn to scale.

3 The radius of the circle is 4 cm. Find its diameter.

Diameter = 2 ×

= cm

4 The diameter of the circle is 14 m. Find its radius.

Radius = ÷ 2 = m

4 cm

14 m

2 Measure the radius of each circle. Calculate the diameter.

D

radius

O

E

O

F

O

5

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