Page 6 - 新思维数学学生用书3 样章

1 Numbers to 1000
Worked example 1
What is the value of the ringed digit in this 3-digit number?
4 7 2
It helps to say the number
472 is four hundred and
out loud.
seventy-two.
The 7 is in the tens place.
You say the value of each
digit as you read it.
The value of the 7 is 7 tens,
so it is 70.
5 Multiplication and division
3 Sort these numbers into the correct place on the Venn diagram.
45, 120, 132, 401, 740, 215, 805, 490, 96, 387, 350, 675.

6 3 7
9
10
numbers to 1000
3
9 4
9 21

2 53
76 8

multiple
multiple
of 10
of 5
Which tens values have not been used in these numbers?

5 What is the value of the ringed digit in each 3-digit number?

How to use this book
Is it easier to find the value of the hundreds, tens or ones digit?
Why do you think that is?
An investigation to carry out Think like a mathematician
What do you notice about the Venn diagram? Describe the numbers in
each part of the Venn diagram, using the words multiple, odd and even.
with a partner or in groups. 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.

Where this icon appears , the What could the other two numbers be?

Compare your numbers with those of someone else in your class.
activity will help develop your If your numbers are different, can you explain why?
Think like a mathematician 1
Sofia says that if you are sorting multiples of 2, 5 or 10 in a
skills of thinking and working mathematically.
Venn diagram, the multiples of 10 always belong in the overlap
12 8 Time and it does not matter which two sets of multiples you sort.
Do you agree with Sofia? How do you know?
Questions to help you think Can you explain to a partner how to write
Arun says that multiples of 10 are special numbers.
digital numbers?
Why do you think Arun says that?
about how you learn. Which type of clock do you like using the most? Why?
Look what I can do!
72
What you have learned in I can read and record time using analogue clocks.
I can read and record time using digital clocks.
the unit. I can link analogue and digital times. 1.3 Estimating and rounding
Questions that cover what you Check your progress
Check your progress
1 Write the time that is shown on each clock.
have learned in the unit. 1 Complete these pieces, which are from a 1 to 1000 number strip.
b
a

11 12 1 11 12 1
10 2 10 2
9 3 9 3
8 4 8 4
7 6 5 7 6 5
765
c d
11 12 1 384 11 12 1
10 2 10 2
9 3 9 3
8 4 8 4
7 6 5 7 6 5
2 What is the value of the ringed digit in each 3-digit number?

Dicey fr
r
oject 4 Dicey fr
r
P
oject 4
Project 4 Dicey fractionsactions Project 4 Dicey fractionsactions
P
56 7
7 29
At the end of several units, Project 4 Project 4
6 7 4
92 3
there is a project for you to 8 88 4 4 4
Dicey fr
Dicey fractionsactions
3 Write the missing numbers.
carry out using what you 128 Sofia and Arun are playing a fraction game. They draw a grid
Number
Sofia and Arun are playing a fraction game. They draw a grid
Round to the nearest 10
Round to the nearest 100
like this and write a denominator of 10 in each box:
like this and write a denominator of 10 in each box:
234
have learned. You might 471 10 10 10 10 10
10
make something or solve 896 10 10 10 10 10
10
750
a problem. 10 10 10 10 10
10
303
e it in turns to r
oll a 1-6 dice.
E
T
They take it in turns to roll a 1-6 dice. Every time, they write the they write the
hey tak
very time,
987
t is r
tor in one of
a
number tha
number that is rolled as the numerator in one of the boxes. the boxes.
olled as the numer
The winner is the player who makes a line of three boxes that adds up t adds up
x
ee bo
he winner is the player who mak
es tha
thr
T
es a line of
Projects and their accompanying teacher guidance have been written by the NRICH
to one whole. (The line of three can be a straight line in any direction.)ection.)
ee can be a str
thr
(T
he line of
to one whole.
aight line in any dir
Team. NRICH is an innovative collaboration between the Faculties of Mathematics 21
ter Sofia and
Her
e of
the game af
Here is a picture of the game after Sofia and Arun have been Arun have been
e is a pictur
playing for a lit
playing for a little while:tle while:
and Education at the University of Cambridge, which focuses on problem solving and
3
3
1
1
10
10
10
10
10
10
on creating opportunities for students to learn mathematics through exploration and
5
1
1
5
discussion. 10 10 10 10 10 10
4
5
4
5
10 10 10 10 10 10
He r
It is Arun’s turn. He rolls a 5.olls a 5. 5
s turn.
It is
Arun’
e do you think
Wher
Where do you think Arun should put the 5? Why?Why?
Arun should put the 5?
times with a par
Have a go a
Have a go at playing this game lots of times with a partner.tner.
t playing this game lots of
Do you have any good ways of trying to win? trying to win?
Do you have any good ways of
Does it matter if you go first or second? you go first or second?
ter if
t
Does it ma
197 197