Page 5 - 新思维数学学生用书3 样章

How to use this book

How to use this book

3D shapes
4
In this book you will find lots of different features to help your learning:

Questions to find out what Getting started

you know already. 1 Shapes can be grouped using their faces, vertices or edges.
Draw arrows to sort these shapes into a group.
4 3D shapes
Some will go into more than one group.
3 Addition, subtraction and money
4.1 3D shapes
3.3 Money
What you will learn in We are going to …

the unit. We are going to … • learn about prisms and find what is the same and what is
different between prisms and pyramids
• use the decimal point to show two different units of money
in the same amount • build and name 3D shapes
• describe and sketch 3D shapes.
• add amounts of money and use this to find the change 5 Multiplication and division more than five
all faces
one or more
• subtract amounts of money to find the change. curved surfaces rectangular vertices
You will have seen 3D shapes all around you but do
Important words that you know what they are? Do you know what a prism is? apex
Think like a mathematician 2

Adding and subtracting money is the same as adding
prism
buy change
and subtracting numbers. You must make sure that Can you find prisms at school and at home?
you will use. This section will help you to recognise prisms and pyramids and
How is finding a fact family for a multiplication fact the same as
decimal point
2 Name two 3D shapes that have fewer than six vertices.
you take note of the currency units when you add and
money notation
finding a fact family for an addition fact?
subtract. $5 – 5c does not leave you with no money! use other more familiar 3D shapes in different puzzles and activities.
spend
How is it different?
Worked example 1
1 Numbers to 1000
A prism has two ends that are the same shape and size.
Step-by-step examples It has flat faces.
6 Choose three single-digit numbers and three 2-digit
Worked example 1
Worked example This unit will introduce you to prisms. You will compare prisms
Which shapes are not prisms?
numbers to multiply by 10. Record your multiplications.
What is the value of the ringed digit in this 3-digit number?
showing a way to and pyramids to find what is the same and what is different
c
a
b
d
How do I use a decimal point to record $4 and 24c?
about them. You will use what you know about 3D shapes to
4 7 2

solve a problem. The number of dollars is written × 10 = It helps to say the number × 10 =
$4 and 24c
identify, build, name, describe and sketch them.
472 is four hundred and
after the dollar sign ($), before the
decimal point. seventy-two. × 10 = out loud. × 10 =
The 7 is in the tens place.
You say the value of each
There are often The number of cents is written after digit as you read it.
The value of the 7 is 7 tens,
54
g
e
f
the decimal point.
so it is 70.
many different ways to The dollar sign tells you it is money, × 10 = × 10 =
= $4.24
Look at the ends. Look at the faces.
so you don’t need to use the c for
a, c, f and g are not prisms because they do not all have flat faces
5 What is the value of the ringed digit in each 3-digit number?
solve a problem. cents as well. or two ends that are the same shape and size. 9
10
6 3 7
9 21 7 Explain what happens to a single-digit number
9 4
3

2 53
56 76 8 and a 2-digit number when it is multiplied by 10.
Which tens values have not been used in these numbers?
44 Is the answer always an even number? Why?
You could use the place value chart to help you.
These questions will help you
100s
10s
Is it easier to find the value of the hundreds, tens or ones digit? 1s
Why do you think that is?
develop your skills of thinking
and working mathematically.
Think like a mathematician

Tomas makes nine 3-digit numbers using a set of place value cards.

Seven of the numbers are 473, 689, 358, 134, 925, 247 and 791.
What could the other two numbers be?
Compare your numbers with those of someone else in your class.
8 A school has 23 boxes of 10 pencils.
If your numbers are different, can you explain why?
How many pencils does the school have? Show your
4 method. 10 Pencils
12
74