Prim Maths 3 2ed TR Learner Book Answers
Prim Maths 3 2ed TR Learner Book Answers
11 772
32 51 52 53 792
42 62
2 428 = 400 + 20 + 8, 913 = 900 + 10 + 3,
576 = 500 + 70 + 6; 395 = 300 + 90 + 5.
2 42 87
3 a 215
b 632
0 10 20 30 40 50 60 70 80 90 100
4 564
3 70, 30, 50, 60
5 3 tens, 30; 9 ones, 9; 9 hundreds, 900; 9 tens, 90;
Exercise 1.1 8 ones, 8; 2 hundreds, 200.
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camels apple
meerkats grapes
fish
banana
penguins
total 49
seals
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4 3D shapes
Getting started
1 one or more curved surfaces: sphere, cylinder;
all faces rectangular: cube, yellow cuboid, blue
cuboid; more than five vertices: cube, yellow
cuboid, blue cuboid
2 Fewer than six vertices: sphere, cylinder,
triangle-based pyramid, square-based
pyramid.
Exercise 4.1
1 Curved edges Straight edges A prism has two ends that are the same shape
and size. The faces are flat. The remaining
tinned
shapes don’t have those properties.
tomatoes
6 Name of Prism, Properties
shape pyramid
or neither
cube prism 12 edges
biscuits cereal
6 faces
8 vertices
cylinder neither 0 edges
Learners’ own labels, lines and shapes. 2 faces
2 Learners’ own answers. and 1
curved
3 Learners’ own answers. surface
4 What can it be? It is a … 0 vertices
A shape that has faces that square- triangular prism 9 edges
are triangles and a square based prism 5 faces
pyramid 6 vertices
A shape that has no vertices sphere hexagonal prism 18 edges
A shape that has 8 faces hexagonal prism 8 faces
prism
12 vertices
A shape that has 6 faces cuboid
square- pyramid 8 edges
A shape that has a curved cone based 5 faces
surface and a circular face pyramid
5 vertices
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1 rings around 76, 532, 210, 1000, 784, 38, 670 100s 10s 1s
2 A multiple of 2 is made up of groups of two. 2 8
Even numbers of objects can always be put 2 8 0
into groups of two (pairs).
8 23 × 10 = 230, so 230 pencils.
3 Multiples of 5 circle: all numbers are multiples
of 5. The numbers on the left are all odd 9 16, 21, 26, 31
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10 table:
6 Measurement, area a 110 cm b 100 cm
and perimeter bed:
a 280 cm b 3 m
Getting started road sign:
1 a–d Learners’ own answers. a 20 km b 15 km
2 a–d Learners’ own answers.
Think like a mathematician
Exercise 6.1 The shortest route Silas can take while keeping to
the edges of the bricks is to travel one and a half
1 Learners’ own answers. 1
lengths and two widths. 30 × 1 + 15 × 2 = 75 cm
2
2 Learners’ own answers. Learners’ own answers on other routes.
3 Distance with 2 continents: km
Exercise 6.2
Length of a seal: m
Size of a saucepan: cm 1 These shapes all have 4 sides, straight sides
and lines of symmetry.
An Olympic marathon: km
2 It has 3 sides and 3 vertices. All sides are
Length of your foot: cm straight.
Length of a rowing boat: m 3 5 × 5 square with a perimeter of 20 cm
Width of a mobile phone: cm 6 × 6 square with a perimeter of 24 cm
Length of a golf course: km The perimeter of each square in the sequence
Height of your bedroom door: m is 4 cm longer than the perimeter of the
previous square.
Width of a glove: cm
4 a regular:
4 Learners’ own answers.
5 Learners’ own answers.
6 Learners’ own answers.
7 a learners’ own estimates; 4 cm b irregular:
b learners’ own estimates; 2 cm
8 a 7 m = 700 cm
1
b 250 cm = 2 and m
2
1
c 3 and m = 350 cm
2
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Exercise 6.3
1 a 20 square units b 16 square units
c 3 square units d 6 square units
2 Yes (6 square units). Learners’ own answers.
3 a each side 9 units
b perimeter 36 units (9 + 9 + 9 + 9)
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1 2 1 2 e 17 minutes past 4
3 a = , =
2 4 5 10
f 34 minutes past 8 or 26 minutes to 9
b Learners’ own answers.
3 a and e, b and d, c and f.
4 Learners’ own answers.
4 Learners’ own answers.
2 1
5 = , so the learner would need to draw
4 2 5 a 18 minutes past 6
another two triangles. Where the learner b 14 minutes to 3
positions the triangles is their choice.
c 24 minutes past 6
Think like a mathematician d 42 minutes past 9 or 18 minutes to 10
1 1
a
2
is shaded, is not shaded.
2 Think like a mathematician
b Learners’ own designs and answers.
a Five light bars can make 2, 3 or 5.
Check your progress b 4, 5 and 6 light bars can match the number
3 shown on the display (that is, 4 light bars can
1 a 1
10 b make the number 4; 5 light bars can make
2
the number 5; and 6 light bars can make the
2 number 6).
Exercise 8.1
1 a minute hand pointing to 3; time around 9 More addition and
quarter past 3
b minute hand pointing close to 7; time subtraction
around 25 minutes to 7
c minute hand pointing to 12; time is Getting started
12 o’clock
1 estimate 520 + 350 = 870; learners’ own choice
2 b 13 minutes past 3 of method, 519 + 348 = 867
c 27 minutes past 9 2 estimate 380 − 170 = 210; learners’ own choice
d 52 minutes past 1 or 8 minutes to 2 of method, 375 − 168 = 207
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5 a = 92
1 b 300 + 150 + 2 c 600 + 160 + 3
d 200 + 100 + 9
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4
77 33 23
3
Complement 2
Number
to 1000 1
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1 a odd multiples of 5
Numbers 1 to 20 31 25
1 17
5 40
19 19
multiples of 2 multiples of 3
29 35
2 4 multiples 10
of 2 and 3 3
8 10 8 16
6 12 9
14 16
18 15
20
5 17 4 a three times
7 11 13 b Learners’ own answers.
Multiple of 3 18 12 24 15 21
and division
Not a multiple of 3 10 16 20 22 11 17 23 Getting started
1 8 × 4 = 32, 32 = 8 × 4, 4 × 8 = 32, 32 = 4 × 8,
b Learners’ own answers. 32 ÷ 8 = 4, 4 = 32 ÷ 8, 32 ÷ 4 = 8, 8 = 32 ÷ 4
3 a–e Learners’ own answers. 2 Add the multiplication tables for 5 and 3
4 Learners’ own answers but labels can be two or for 6 and 2; double and double again
arms/not two arms, four arms/not four arms, the multiplication table for 2; double the
odd number of legs/not odd number of legs multiplication table for 4.
and even number of legs/not even number 3 a 24 b 4 c 42
of legs.
d 50 e 10 f 130
Think like a mathematician g 72 h 2 i 0
Learners’ own answers.
Exercise 11.1
Check your progress 1 24, 8, 18, 63, 48, 36
1 a Three monsters have two legs, two 2 Each product is the result of a number
monsters have three legs, two monsters multiplied by itself.
have four legs.
3 24 ÷ 8 = 3 or 24 ÷ 3 = 8; 8 ÷ 4 = 2 or 8 ÷ 2 = 4;
b Learners’ own answers. 18 ÷ 6 = 3 or 18 ÷ 3 = 6; 63 ÷ 9 = 7 or 63 ÷ 7 = 9;
c For example, sort them by the number 48 ÷ 6 = 8 or 48 ÷ 8 = 6; 36 ÷ 4 = 9 or 36 ÷ 9 = 4
of arms.
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5 a 54, 63, 72; rule is + 9 4 46 ÷ 4 = 11 r2, so 12 tubes are needed for 46
b 38, 43, 48; rule is + 5 balls.
c 115, 123, 131; rule is + 8 5 36 ÷ 5 = 7 r1, so each child gets seven marbles
d 99, 90, 81; rule is – 9. with one marble left over.
6 100, 92, 84, 76, 68 6 37 ÷ 10 = 3 r7, so four benches are needed for
37 children.
Exercise 11.2 7 Learners’ own answers.
1 Learners’ own order of multiplication. Check your progress
a 5 × 4 × 3 = 60 b 6 × 5 × 3 = 90
c 6 × 4 × 2 = 48 d 8 × 3 × 2 = 48 1 Learners’ own answers.
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5 7 9 1 1 1 1
1 1 1 1 3 d < e > f > .
20 10 10 5 10 2 3
2 3 4 10 4
1 1
6 of something is more than of the same
10 X 5 2 15 3 4
1 1
something, so of $100 is more than
3 4
6 27
of $100.
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3
0 4 1 3 2 2
+ = 1, + = 1, + = 1 2 a The chocolate bar must have the same
4 4 4 4 4 4 mass as two muffins, so one muffin must
4 3 1 have a mass of 50 g.
4 − =
5 5 5 b Each side of the scales has a mass of 150 g.
5 Learners’ own diagrams. 3 a 500 g < 5 kg b 10 g < 1 kg
1 1 1
a estimate: < , 0 b estimate: < , c 1000 g = 1 kg
2 2 5
1 7 1 1 4 a 80 g b 70 g
c estimate: > , d estimate: < ,
2 10 2 4
c 500 g d 4 g
5 Learners’ own answers.
0 5 1 4 2 3 3 2
6 Learners’ own answers.
6 1 − = , 1 − = , 1 − = , 1 − = ,
5 5 5 5 5 5 5 5
4 1 5 0 Think like a mathematician
1 − = , 1 − = = 0
5 5 5 5 For example rows could be:
c $24 d $15 Columns can use the same amounts as above but
set vertically.
Check your progress Challenge answer, for example:
1 1 1 1 1
1 , , , , 500 g 50 g 450 g
10 5 4 3 2
250 g 350 g 400 g
1 1 4 2 1 1
2 a < b > c < 250 g 600 g 150 g
4 3 5 5 10 5
5 1 4 10 2 3
d = e = f < Within the Challenge square, there are eight ways
10 2 4 10 3 3
to make a total of 1 kg: three rows, three columns
3 Learners’ own diagrams. and two diagonals.
1 2
a estimate: < ,
2 10 Exercise 13.2
1 5
b estimate: > , = 1 1 a A: 250 ml; B: 750 ml; C: 500 ml
2 5
1 2 b container B, container C, container A
c estimate: > ,
2 3
c The same because 1000 ml is the same as
1 3 1 litre.
d estimate: > ,
2 4
d Learners should have drawn a line at the
500 ml mark.
13 Measure 2 a
1
250 ml = litre b
3
750 ml = litre
4 4
Getting started c 1000 ml = 1 litre d 8 cans = 2 litres
1 Learners’ own answers. e 12 cans = 3 litres f 16 cans = 4 litres
3 Marcus is incorrect. His method will only
Exercise 13.1 work if he has two jugs that are the same size
1 One pear has a mass of 40 grams, so 4 pears and with the same capacity. Otherwise, a tall
have a mass of 160 grams. narrow jug could have a higher level of water
than a wider jug but still contain less water.
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b Exercise 14.2
11 12 1
1 a 8:50
10 2
b 8:45
9 3
c Bus 1 and Bus 2
8 4
7 5 d Razaan is correct. This timetable shows
6 the bus travelling in one direction only. It
does not give information about the buses
c travelling in the opposite direction, from
school to Razaan’s home.
11 12 1
10 2 2 a 11:23
9 3 b 2:58
c Train 2 and train 6
8 4
7 6 5 d 11:25
e 8:01
d
Think like a mathematician
11 12 1
10 2 Learners’ own answers.
9 3
Check your progress
8 4
7 5 1 a two months
6
b 31 days
c two weeks
Exercise 14.1 2 a Wednesday
1 a–g Learners’ own answers. b Thursday
c 1:00
2 a 26 days b 22nd March
d Tuesday
c 3rd February d 9th February
3 a 7:30
3 a 6th June
b 8:42
b 11th July
c the second train
c seven days
d Stefania was born in 2010, so she will be
20 years old in 2030.
15 Angles and
4 a 174 days
b 15 years old movement
c Song’s holiday is longer by 1 day. Getting started
5 a Saturday 19th April
1 a
b Monday 28th April
6 two years
7 Learners’ own answers.
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Exercise 16.1
1 It might happen. One domino has more than
eight spots.
b
2 Learners’ own answers.
3 a Spinner A could land on 1, 2 or 3.
b Spinner B could land on 1, 2, 3, 4, 5, 6, 7
or 8.
c Spinner A is more likely to land on 3,
because there are fewer options. Spinner B
has more options.
d Learners’ own results. c
e Learners’ own answers.
17 Pattern and 3 a
symmetry
Getting started
1 Learners’ own answers.
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A circle has an infinite number of lines
of symmetry; only four are marked in the
diagram above.
8 Learners’ own answers. Marcus is correct: a
circle has infinite lines of symmetry.
c Learners’ own answers.
9 Learners’ own answers. Only the second and
4 Diagram c shows symmetry. third logos are symmetrical.
Symmetry means that when an object is split
along a line of symmetry, it will produce two Think like a mathematician
mirror images. Learners’ own answers.
5 Learners’ own answers.
Exercise 17.2
6
1 a 9 + 3 = 12, 12 + 3 = 15, 15 + 3 = 18
b 21
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