lOMoARcPSD|42896089 Prim maths 4 2ed tr workbook answers Business (Myanmar International Business Academy) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE Workbook answers 1 Numbers and the number system d Exercise 1.1 Focus 1 a b 2 28, 34 3 33 circled 4 2020, 2031, 2042, 2053, 2064 5 a 1, −2, −5, −8 c 990, 955, 920, 885 add 11 110 1, 4, 9, 16, 25, 36, 49, 64, 81, 100 (multiply each counting number by itself – square numbers) Exercise 1.2 Focus b −3, −1, 1, 3 Practice 1 Arrow pointing to −5. 2 a 5° C b −3 ° C 3 a −3 b 0 c −2 d −9 a −2 circled difference: 4 4 6 750 and 900 circled b –1 circled difference: 2 7 No. All terms are 1 more than a multiple of 7, and 77 is a multiple of 7. c 4 circled difference: 8 8 302 9 1001, 1006, 1011, 1016, 1021, 1026, 1031, 1036, 1041 Practice 5 −7 and 4 6 10 1 1 and 96 14 −10 −4 −1 0 −4 and 12 10 20 30 40 °C 2 Challenge 7 a 11 15 8 7 ° C (Do not accept 7) Add 5 to previous term (you add one more each time). 12 24 and 44 Challenge 13 a b c linear ‘add 4’ first term 5 21 and 25 –5 −10, 10 and 15 –3 –2 –1 0 1 term-to-term rule 10 9 ° C non-linear first term 3 term-to-term rule ‘add 8 then one less each time’ 29 and 33 11 19 ° C non-linear first term 3 rule ‘double’ 48 and 96 13 No, together with an explanation that the sequence continues −10, −7, −4, −1, 2 . . ., and 0 is not included. term-to-term 14 Examples (other answers are possible): 1 9 b a 1, 3, 6, 10 (add one more each time) b 6, 13, 20 (add 7) c 3, 6, 9, 12, 15 (add 3) 12 −40 and 80 ⭐ Downloaded By Success Groups Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE Exercise 1.3 Challenge Focus 11 Nine hundred and seventy-five thousand three hundred and ten 1 One thousand, four hundred and fifty 2 Circle 5005 3 April 12 1 4 305 469 = 300 000 + 5000 + 400 + 60 + 9 5 Fourteen thousand, three hundred and fifty two, 14 352 6 6 D 2 I T H R 3 E G I I G E × 10 4 T H Z 60 × 100 5 600 S E V E N T U R Y × 10 R 32 6 × 10 F O 320 × 100 13 a 3200 d × 10 35 800 b 30 100 e 304 000 14 350 ÷ 10 1400 14 100 35 × 10 = 350 ÷ 10 2 Time and timetables 140 ÷ 100 c Exercise 2.1 ÷ 10 Focus 8000 1 ÷ 10 800 ÷ 100 80 2 ÷ 10 3 Practice 7 Nine thousand, nine hundred and thirty 8 130 030 9 a A b C c D d C e D f B 4 a 300 b 240 c 21 d 24 e 2 f 10 Half past four – 04:30 4 o’clock – 04:00 half past three – 03:30 a 3 weeks b 8 years c 21 months 9:15 circled 10 D 2 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE Exercise 2.2 5 eight fifty a.m. or ten to nine 11 10 12 Focus 1 2 9 3 8 7 three thirty p.m. or half past three 6 8 4 7 6 5 11 10 12 1 9 3 8 c 35 minutes 2 a 3 50 minutes 40 minutes b 17 minutes a 10 minutes b 30 minutes c train 2 or 10.20 a.m. train Practice 4 a 15 minutes c 32 minutes 5 a 35 minutes 6 14:43 7 2 hours 4 7 b 2 6 b 20 minutes b 3.55 p.m. 5 Joe is wrong. He should add 12 to the hours, not the minutes. Practice 8 25 minutes 11 12 1 10 2 9 3 eight thirty a.m. or half past eight in the morning 7 a 5 afternoon 6 1 4 Challenge 8 8.35 a.m. or 25 minutes to nine 9 a 12:45 b a 104 b 630 10 5 times c 62 d 72 A 5.30 p.m. B 3.25 a.m. C 5.15 p.m. D 10.20 a.m. 11 Missing times (from the top): 11.13 a.m. 10.35 a.m. 11.37 a.m. 10.53 a.m. 11.55 a.m. 9 quarter past 7 in the evening — 19:15 twenty past ten in the morning — 10:20 half past two in the afternoon — 14:30 quarter to eleven in the morning — 10:45 10 a 10:00 b 18:00 c d 23:00 08:00 11 15:45 → 16:45 → 17:45 → 18:45 → 19:45 Challenge 12 16:10 07:15 15 minutes 3 Addition and subtraction of whole numbers Exercise 3.1 Focus 21:45 13 a 3.10 p.m. b 11.55 p.m. c 11.10 a.m. d 3.05 a.m. 1 63 2 700 3 46 + 54 = 100 4 513 14 08:10 15 15:25 16 Sara (85 secs), Petra (88 secs), Ingrid (91 secs), Milly (94 secs), Neve (100 secs) 3 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 14 5 30 10 10 40 30 50 60 20 40 20 20 Practice 6 13 7 1250 8 22 50 40 30 15 3 1 9 5 5 4 3 1 4 20 2 2 56 The numbers at the end of each line are interchangeable. 36 Exercise 3.2 Focus 63 +20 1 37 + 24 = 61 +3 37 57 100 +1 60 61 +40 37 74 + 38 = 112 74 –2 10 Δ = and = 4, Δ = 1 and = 3, Δ = 2 and = 2, Δ = 3 and = 1, Δ = 4 and =0 112 –20 2 11 16 + 24 or 14 + 26 –5 56 – 25 = 31 31 Challenge –20 65 – 19 = 46 65 +1 45 4 56 36 12 8 13 7972 114 46 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 3 749 = 700 + 40 + 9 568 = 500 + 60 + 8 1200 + 100 + 17 Exercise 3.3 Focus = 1317 1 H 2 16 3 odd + odd = 42 106 even even 4 a b 150 14 odd + even = odd Practice even + even = 4 5 31 13 60 41 18 31 23 25 6 + 1 1 7 a 8 594 17 95 48 37 5 Never true. Counter example: 1 + 3 + 5 = 9 which is odd (odd + odd = even, then even + odd = odd) 20 32 28 19 17 6 True 7 8 8 6 4 9 8 1 4 Add the ones 7 0 8 0 0 4 Add the tens Add the hundreds 762 5 b 43 111 odd Not true 324 Leroy adds two odd numbers and an even number. Odd + odd + even = even and 33 is odd. odd − odd = even so the statement is never true. Do not accept one numerical answer such as 13 − 9 = 4 and 4 is even. Challenge 9 16 41 90 248 511 1308 even, even, odd 10 true, false, true, false 11 The sum of three odd numbers is 22. ✗ Challenge 9 b Practice 47 7 1 1 2 Always true, for example, 1 + 3 = 4, 25 + 13 = 38 (odd + odd = even) 46 29 67 30 a 106 72 150, 250 and 350 or 50, 250 and 450 10 74 + 26 or 76 + 24 12 Sometimes true. 4 + 6 + 8 + 10 = 28 2 + 4 + 8 + 12 = 26 28 ÷ 4 = 7 26 ÷ 4 = 6 remainder 2 11 891 5 12 a 61 − 34 = 27 b 13 a Largest number 1395 b smallest number 603 615 − 151 = 464 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 4 Probability Exercise 4.1 5 Multiplication, multiples and factors Focus Exercise 5.1 1 2 3 A dice lands on an even number. No chance You will change into a fish tomorrow. Poor chance You will breathe today. Even chance You will turn left today. Good chance You will become famous tomorrow. Certain Focus 1 Multiples of 10 are coloured twice because they are multiples of 2 and multiples of 5. 2 × 3 4 5 There is a good chance of taking a black ball from the bag. 2 6 8 10 There is a poor chance of taking a white ball from the bag. There is no chance of taking a red ball from the bag. Answer depends on the outcomes of the learners’ investigations. 4 12 16 20 6 18 24 30 4 8 3 Any number except 1 to 6. 1 Practice 4 a False b True c True d False e True f True 2 3 8 1 8 2 4 5 4 9 Learners’ own sentences. 6 6 5 C 6 Table values depend on the outcomes of learners’ investigations. a There is no chance of getting 11. b It is certain to be a number less than 11. c There is a poor chance of getting a 2. 8 4 5 7 3 6 9 0 1 36 2 18 3 7 4 12 9 36 a Example: There is no chance of taking a red T-shirt from the suitcase. b Example: It is certain they will take a T-shirt from the suitcase. c Example: There is a poor chance of taking a white T-shirt from the suitcase. 3 d Example: There is a good chance of taking a T-shirt that is not white from the suitcase. 5 e Example: There is an even chance of taking a black T-shirt. EDBCA 9 Answers will vary from learner to learner. 4 1 and 18, 2 and 9, 3 and 6. Challenge 8 1 2 45 1 6 15 45 9 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE Practice 13 × 3 7 9 4 2 5 15 35 45 20 10 6 18 42 54 24 12 3 9 21 27 12 6 8 24 56 72 32 16 4 12 28 36 16 8 × 3 5 7 6 10 3 9 15 21 18 30 5 15 25 35 30 50 7 21 35 49 42 70 6 18 30 42 36 60 10 30 50 70 60 100 6 15 5 6 30 3 63 7 2 a c < > 8 7 17 9 49 6 36 27 5 7 42 9 7 35 4 37 56 6 47 57 7 b d = = 67 77 8 87 97 10 11 1 5 25 2 10 16 13 Start 9 4 6 17 14 18 20 3 15 7 14 24 + 39 or 29 + 34 15 11 1, 2, 3, 4, 6 and 12 circled Challenge 12 5 30 6 24 35 4 7 9 5 12 7 8 5 6 2 3 7 7 1 3 2 6 3 9 20 16 2 and 6 Exercise 5.2 Focus 45 1 21 4 45 63 4 7 2 5 20 28 1 3 4 36 30 9 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 2 13 39 3 6 2D shapes 34 65 15 68 5 2 238 Exercise 6.1 7 14 Focus 1 5 14 42 3 56 12 3 156 4 522 5 1 × 36 = 36 Enter 105 4 21 2 × 18 = 36 15 63 3 3 × 12 = 36 Practice 6 a left-hand side: 9 × 2 × 5 = 18 × 5 = 90 right-hand side: 9 × 2 × 5 = 9 × 10 = 90 right-hand side is better b left-hand side: 2 × 5 × 7 = 10 × 7 = 70 2 a right-hand side: 2 × 5 × 7 = 2 × 35 = 70 left-hand side is better 7 a b 8 300 × 8, 600 × 4, 400 × 6 and 800 × 3 circled 9 120 and 441 200 10 250 × 3 150 × 5 c 414 375 × 2 684 125 × 6 b Challenge 11 Either girl with an appropriate explanation. for example: Amy because I prefer to find factors of the larger number 6 × 15 = 15 + 15 + 15 + 15 + 15 + 15 = 90 12 a 636 b 1278 c 3584 13 702 14 9 (396 × 9 = 3564) 15 763 × 8 = 6104 8 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE • • • c 7 is a parallelogram is a rectangle has 2 lines of symmetry. Completed tessellating pattern Exercise 6.2 Focus 1 3 Drawing showing tessellating triangles. 14 triangles tessellate in the space. Four lines of symmetry drawn: vertical line down the centre, horizontal line through the centre and two diagonal lines corner to corner. 2 Practice 4 a The shapes are: Triangle, square, triangle, quadrilateral (parallelogram) The new shape has 4 sides and 4 vertices. It has one pair of parallel sides. It is a quadrilateral (trapezium). b Practice Triangle, triangle, triangle, square 4 Two diagonal lines of symmetry drawn on the tile. 5 Octagon Number of lines of symmetry The shapes are: A 8 Triangle, triangle, quadrilateral (parallelogram) B 4 C 0 The new shape has 6 sides and 6 vertices. It has two right angles. It is a hexagon. D 2 6 5 Completed tessellating pattern. The horizontal line circled. Challenge Octagons and squares. 7 Challenge 6 8 Any four from: • has 4 sides • has 4 vertices • has two pairs of parallel sides • has 4 right angles • is a quadrilateral 9 Four lines of symmetry drawn: horizontal, vertical and two diagonal lines. The shapes are: The new shape has 6 sides and 6 vertices. It has one pair of parallel sides. It is a hexagon. c 3 9 a Diagonal lines of symmetry drawn on. b 4 c No, for example, a rectangular pattern can have a horizontal line of symmetry and a vertical line of symmetry, but it cannot have a diagonal line of symmetry. a No more lines of symmetry drawn. b 2 a No lines of symmetry drawn. b 0 10 a Octagon. 8 lines of symmetry drawn. b Pentagon. 5 lines of symmetry drawn. c Decagon. 10 lines of symmetry drawn. Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 7 Fractions 5 Exercise 7.1 6 12 cards Focus 7 7 cm 1 8 8 9 1 of 15 5 2 3 4 3 2 is greater than 2 4 6 Practice This gives the answer 3, but all the other calculations give the answer 2. 10 6 squares, 3 squares, 2 squares and 1 square. Challenge 2 is less than 2 4 3 In order: 2 6 11 15 balloons 2 4 12 10 beads are blue. There are 20 beads 2 3 1 altogether. 2 of 20 = 10 Practice 4 13 1 of 16 = 4 B and E a 6 1 >1> 1 4 6 12 2 <2 12 6 b 1 litre 4 15 Show that 1 of $36 = $12 and 1 of $60 = $15 3 2 > 2 3 12 1 is the smaller fraction but it is a quarter of a 4 larger amount of money. Same amount of space covered (equivalent). 8 4 3 and 5 10 8 Angles 9 Sometimes. If a shape is split into four equal parts it is split into quarters. Exercise 8.1 Focus Exercise 7.2 1 Focus a Angle B circled. b Angle A circled. c Angle B circled. d Angle A circled. e Angle A circled. f Angle B circled. b D circled. 1 Ring around any 3 counters. 2 4 a 1 of 20 – Answer equal to 10 2 B circled. 3 c C circled. 1 of 60 – Answer more than 10 5 Practice 2 1 of 32 – Answer less than 10 4 1 of 30 – Answer equal to 10 3 4 so it is better to have $15. 7 4 1 of 24 = 6 4 14 20 Challenge 10 1 of 20 = 5 4 4 3 litre 4 5 7 and 8 3 a Angle A circled. b Angle A circled. c Angle B circled. d Angle B circled. e Angle A circled. f Angle A circled. $8 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 4 Learners’ answers and explanations. Challenge 5 a 6 Angle of between 70 and 110 degrees drawn. Angle of between 20 and 60 degrees drawn. Angle of between 120 and 150 degrees drawn. b c 7 Challenge Any acute-angled triangle. b Any right-angled triangle. c Any obtuse-angled triangle. d Angles in parts a to c labelled. a obtuse b acute d obtuse e acute c acute 6 B, D, A, E, C Exercise 8.3 7 C, E, A, B, D Focus 8 Learners’ explanations. 1 90 degrees 2 a 45 degrees b 130 degrees c 95 degrees d 30 degrees e 160 degrees Exercise 8.2 Focus 1 2 f p m e o b w z q s m a t v c t o a s w o i f r u e m m e i d x p a q g z a a t k h k g r e a t g d e g r e v j a n g l t u s l l e c u t a w d c k v c v z a j v e r h e s i e b h e r e a v n h g g n acute angle compare degrees estimate greater obtuse right smaller 3 Obtuse 4 5 Acute Acute Obtuse 6 Practice 4 A – 92 degrees, B – 169 degrees, C – 14 degrees, D – 47 degrees, E – 132 degrees Practice a, b and d circled. 3 All angles in ‘Acute angles’ box are less than 90 degrees. All angles in ‘Obtuse angles’ box are less than 180 degrees, but more than 90 degrees. start 120 45 60 10 50 80 100 130 165 35 65 20 50 10 100 70 80 150 100 170 175 130 145 160 60 30 70 40 20 70 20 40 20 160 70 150 110 135 150 110 50 120 40 70 165 10 60 100 160 110 30 155 125 105 170 60 30 70 60 30 40 80 145 end 120 a 4 right angles b 360 degrees c 3 turns d 270 degrees a Estimate between 5° and 25°. b Estimate between 91° and 110°. c Estimate between 150° and 170°. d Estimate between 35° and 55°. e Estimate between 70° and 85°. f Estimate between 125° and 145°. Learners’ answers and explanations. Challenge 7 a 8 For every right angle there is 90 degrees of turn. 9 a Angle between 85° and 95° drawn. b Angle between 37° and 53° drawn. c Angle between 10° and 30° drawn. d Angle between 127° and 143° drawn. e Angle between 95° and 110° drawn. f Angle between 150° and 170° drawn. 5 11 a 3 right angles b 90 degrees Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 9 Comparing, rounding and dividing Exercise 9.2 Focus 1 24 divided by 2 3 4 5 6 7 8 9 10 Remainder Exercise 9.1 0 0 0 4 0 3 0 6 4 1 a 2 85 3 a 5650 5656 6505 6550 6555 2 There is no remainder when 24 is divided by 2, 3, 4, 6 and 8. There is the same remainder when 24 is divided by 5 and 10 or any other relevant observation. 13 jugs b 1234 1432 2134 2341 2413 3 a 4 a 8216 > 8126 6031 > 6013 4 16 packs 5 6162, 6164, 6166, 6168 5 16 and 8 Focus b 3510 94 c 3490 4660 86 b Practice b 13 12 Practice 6 a b 7 Number Rounded to the nearest thousand 4155 3500 c 3000 5000 6 7 children Rounded to the nearest hundred Rounded to the nearest ten 7 8 boxes 8 4 photos 9 85 4000 4200 4160 4505 5000 4500 4510 5455 5000 5500 5460 10 1 and 36, 2 and 18, 3 and 12, 4 and 9, 6 and 6 (numbers in any order) Challenge 8 3170 and 3180 11 10 9 Learners’ own numbers. 12 Mercury 10 8800 metres 11 a 4000 13 b 30 000 c 500 000 7 Challenge 12 21 36 12 a D A B C 17 E 1500 1600 1700 1800 1900 2000 2100 b 855 900 < 897 910 98 150 > 91 899 500 779 < 686 400 259 420 > 100 192 12 18 45 CE Isaac Newton Carl Gauss Leonhard Euler Ada Lovelace Alan Turing 13 455 119 > 455 110 51 15 6 30 10 The number in the outer circle is the number in the inner circle divided by 3. Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 3 3 9 15 15 45 75 35 85 7 60 17 12 0 The number in the outer circle is the number in the inner circle divided by 5 4 14 Coconuts cost $2 each. How many coconuts can be bought for $15? A minibus holds 12 people. 50 people go on an outing. How many minibuses are needed? 2 3 4 5 6 7 8 Question: How many seeds are there in a packet? I will count how many seeds are in each packet. I will record the number of seeds in a table or dot plot. Round up 14 peaches are put in bags. Each bag holds 4 peaches. How many full bags are there? 1 Number of green sweets in the packets Practice 5 a Round down 15 1 and 60, 2 and 30, 3 and 20, 4 and 15, 5 and 12, 6 and 10 (numbers in any order). Number of cars How many hours? 10 3 11 2 12 0 13 5 14 2 b 10 Collecting and recording data Exercise 10.1 Focus 1 2 13 Number of birds How many days? 3 2 4 3 5 4 6 2 7 2 8 1 a 1 b 6 10 11 12 13 14 Number of cars each hour 6 7 c 6 a 0 b d Individual answers. 14 c 5 How many cubes can my friends hold in one hand? People I will use: names of friends. Table completed individually. Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE Challenge 8 a b 3 6 9 12 15 18 21 24 27 30 = = = = = = = = = 4 8 12 16 20 24 28 32 36 40 c 2 4 6 8 10 12 14 16 18 20 = = = = = = = = = 3 6 9 12 15 18 21 24 27 30 2 a 1 5 2 3 , , , 3 8 3 4 b 1 2 5 7 , , , 2 3 6 8 3 a < b < Number of seeds Number of packets 21 1 22 3 23 4 24 3 25 0 26 1 Practice 4 b H and P 1 2 5 0 1 4 21 22 23 24 25 a 7 3 >1 8 4 5 >2 8 4 26 Number of packets d e 0 f Answers could include: Challenge Dot plot 8 4 It is easier in a dot plot to see which categories have the most and least number. It is easier in a dot plot to count the number that is more or less. 9 11 Fractions and percentages Exercise 11.1 Focus 1 14 a 1 2 3 4 5 = = = = = 6 = 7 = 8 = 9 = 10 2 4 6 8 10 12 14 16 18 20 5 6 c 4 >1 8 4 5 >1 8 4 6 >1 8 4 6 >2 8 4 7 >2 8 4 b 1 2 7 >1 8 4 3 6 9 = = 4 8 12 2 4 6 = = 3 6 9 3 = 6 = 30 10 20 100 Question: How many cubes can my friends connect together in a line in one minute? People I will use: Names of friends. Equipment I will need: Cubes, stopwatch (or other device for measuring one minute). Plots will vary. Axis should be labelled ‘Number of cubes in the line’. 2 3 7 >3 8 4 c 21 2 5 3 4 6 1 2 4 10 = = 5 10 25 5 10 20 = = 6 12 24 9 2 and 10 are equivalent so 9 is the odd 3 15 12 2 10 one out. Or and have even numbers as 3 15 numerators so 9 is the odd one out. 12 Other answers are possible. 10 Answers such as: = 20 and = 30 = 40 and = 60 = 60 and = 90 = 80 and = 120 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 11 5 circled 8 12 Yes. Sevenths are greater than ninths because the whole is divided into a smaller number of parts. 12 Investigating 3D shapes and nets Exercise 12.1 Exercise 11.2 Focus Focus 1 1 34% and 25% 2 Shade: a 50 squares b 75 squares c 10 squares 3 a 35% b 36% d 14% e 67% c Practice 4 Shade: a 55 squares b 48 squares c 1 square 5 80 % 67% 75% 25% 20% 50% 33% 50% 6 20% Challenge 7 50% 8 80 learners 9 15% 25% 10 a Shade 10 squares b Shade 10 squares 75% 50% 72% Arrow from ‘face’ to any flat surface on the shape. 2 Arrow from ‘edge’ to any line on the shape. Arrow from ‘vertex’ to any point where three lines meet on the shape. a 12 b 8 c 6 3 a 4 Pentagon, pentagon, rectangle, rectangle, rectangle, rectangle, rectangle b Triangle Rectangle Practice 5 A tetrahedron has: 4 faces, 6 edges and 4 vertices. 6 B, D and E ticked 7 Any pyramid 8 Cone or cylinder Challenge 9 Shape Number of faces Number of edges Number of vertices Cuboid 6 12 8 Triangular prism 5 9 6 Pentagonbased pyramid 6 10 6 Hexagonal 8 prism 18 12 Squarebased pyramid 8 5 5 10 Ticks beside triangular prism, tetrahedron and square-based pyramid. 11 For example, triangular prisms and trianglebased pyramids both have some faces that are triangles. They are different because a triangular prism has 5 faces and a triangle-based pyramid has 4 faces. 15 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE Exercise 12.2 7 445 + 55 or 455 + 45 Focus 8 1 1 Net B circled Challenge 2 Net C circled 9 3 Pentagon-based pyramid circled + Practice 4 Square-based pyramid 5 Net C circled 6 A – cone B – cube C – cylinder 7 9 1 9 3 7 4 2 12 13 more girls A – tetrahedron B – square-based pyramid C – cuboid D – heptagonal prism Possible answers include: • 9 11 605 + 197 = 802 Octagon-based pyramid • 4 10 Possible solutions: 987 − 654 = 300 and 975 − 864 = 111 Challenge 8 5 13 545 + 355 = 900 86 + 814 = 900 791 + 109 = 900 437 + 463 = 900 Exercise 13.2 Focus 1 The net has only 5 faces, but a pentagon-based pyramid has 6 faces. 1 4 2 2 5 The net is missing one triangular face. 10 Octagonal prism 1 4 5 6 3 5 13 Addition and subtraction 2 8 4 5 Exercise 13.1 6 8 3 4 1 6 1 5 Focus 1 474 boys and girls 2 a 3 943 − 349 = 594 4 47 children 66 b 104 Practice 5 6 16 a 8 6 b 4 8 c 8 12 d 2 12 4 a 6 8 b 5 8 5 3 8 3 a 127 + 212 = 339 km b 188 + 334 = 522 km c 156 101 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE Practice 6 7 14 8 8 7 6 4 12 9 4 3 13 8 7 6 3 5 3 9 3 7 8 10 3 9 5 8 15 2 20 1 2 Line 1 = 4 cm Line 2 = 2 cm Line 3 = 4 cm Line 4 = 2 cm Perimeter = 12 cm 52 m 3 Three shapes added to the grid – each 8 cm2. 4 a 3 9 4 9 6 9 1 3 + and 2 + 2 3 3 3 3 5 cm2 b 7 cm2 c 12 cm2 b 18 cm c 16 cm Practice 5 9 b 5 7 Challenge 5 a 6 65 m 7 Four shapes drawn – each with an area of 9 cm2. a 16 cm 7 2 4 5 9 8 3 3 1 8 4 6 Challenge 4 9 3 9 9 12 9 3 5 6 7 7 9 10 16 cm2 1 6 + 3 3 5 20 Focus 5 9 5 9 12 7 20 Exercise 14.1 7 9 8 9 11 4 12 20 14 Area and perimeter 2 9 10 a 21 20 9 20 7 5 8 9 9 Accept correctly simplified answers or mixed numbers. 2 5 + 3 3 6 cm2 b 8 cm2 c 14 cm2 146 mm (allow 144 mm to 148 mm) 11 Four shapes with curved sides – each with estimated area 6 cm2. 3 4 + 3 3 12 82 m Accept equivalents. 13 a Any pair of fractions with a sum of 7 , 8 for example 1 and 6 8 b 8 17 Focus 1 Any pair of fractions with a difference of 3 , for example 4 and 1 8 8 8 Exercise 14.2 a b c Rectangle Correctly labelled sides of 2 cm and 7 cm. 18 cm Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 2 3 a 3 b 12, 15, 18 c 1 cm d 18 cm2 circled a c e 5 b 5 cm 4 d 4 cm The length of the rectangle is the same as the number of squares in a row. 15 Special numbers Exercise 15.1 Focus 1 Practice 4 Rectangle drawn with sides 8 cm and 5 cm. 5 Perimeter = 26 cm a 8 6 7 2 b 32 cm2 circled There are 7 squares in each row and 3 squares in each column. The rectangle is 7 cm long and 3 cm wide. 3 rows of 7 makes 21 squares altogether. The area of the rectangle is 3 multiplied by 7. The area of the rectangle is 21 cm2. a Area = 24 m2 , perimeter = 22 m Area = 80 mm2, perimeter = 36 mm d Area = 49 cm2, perimeter = 28 cm Perimeter = 18 cm 9 a b c Area = 20 cm 10 The area of a rectangle can be calculated by multiplying the length of the rectangle by its width. c 64 cm 2 d 7 m2 b a −15, −10, −5, 0, 5, 10 b The numbers go up by 5 each time. c No. The numbers in the pattern end in 5 or 0, and 71 ends in 1. Practice 5 a −8 ° C, −4 ° C, −2 ° C, 1 ° C, 3 ° C b −13 ° C, −7 ° C, −2 ° C, 4 ° C, 13 ° C c −7 ° C, −6 ° C, −4 ° C, 0 ° C, 6 ° C 6 6 > −17 7 There are many solutions, two of which are: 8 –17 < –13 < –4 < –3, 12 > 7 > 5 –3 < 5 < 7 < 12, –4 > –13 > –17 −4 and 0 circled −16 < −13 0 > −2 2 99 mm −15, −8, −1 6 > −1 > −8 > −15 > −22 10 a Ulaanbaatar Perimeter = 156 mm 60 km −10 ° C, −2 ° C, 2 ° C, 7 ° C −6 or −5 9 Missing sides are 72 mm and 6 mm 11 a c Challenge Missing sides are 9 km and 6 km Perimeter = 30 km 2 −8 ° C, −4 °C, 3 °C, 7 ° C 4 2 Missing sides are 3 m and 1 m Perimeter = 8 m b −1 Challenge 8 −9 ° C, −2 ° C, 0 ° C, 3 ° C 3 b Area = 10 km2, perimeter = 14 km c a b Karachi c −20 ° C, −8 ° C, −3 ° C, 1 ° C, 5 ° C, 14 ° C, 18 ° C 11 −3 > −4 −19 < 11 0 > −1 12 −6 and −14 Exercise 15.2 Focus 1 12 2 63, 70 and 77 3 3 and 7 are factors of 21 because 3 × 7 = 21 21 is a multiple of 3 and 7 because 21÷ 3 = 7 and 21÷ 7 = 3 18 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 4 50 should be in the same part of the diagram as 45. 5 1 × 24, 2 × 12, 3 × 8, 4 × 6 6 A square number is a number multiplied by the same number, 3 × 3 = 9. Practice 7 45 8 All multiples of 4 are even and 5 is odd. 9 64 10 a 25 24 65 b 1, 2, 4, 5, 10, 20 11 1 + 4 in either order 20, 40, 60, 80 9 + 16 in either order Challenge 12 49. It is a square number. 13 36 and 54 or 34 and 56 45 and 63 or 43 and 65 14 a 8 is the odd one out because all the other numbers have 2 digits. b 12 is the odd one out because it is the only one that has 3 as a factor. c 25 is the odd one out because it is the only odd number. d 40 is the odd one out because it is the only one divisible by 10. 15 Is it a negative number? Yes Is the number even? Yes –24 No –14 Is the number even? No Yes Is the number less than –20? No Yes Is the number less than –20? Yes –21 No –5 No Is the number a multiple of 9? Yes 18 No Is the number a multiple of 9? Yes 14 27 No 19 Exercise 15.3 Focus 1 19 232, 234 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 2 divisible by 2 16 Data display and interpretation divisible by 5 302 25 400 52 205 Exercise 16.1 502 203 3 Divisible by 2 – ones digit is 0, 2, 4, 6 or 8 Divisible by 5 – ones digit is 0 or 5 Divisible by 10 – ones digit is 0 Divisible by 100 – tens and ones digits are 0 Focus 1 2 a Pictogram b Dot plot c Carroll diagram d Frequency table a Carroll diagram, because it is a sorting diagram. b Bar chart, because it shows numbers of things so that they can be compared. Practice 4 a 2 b 5, 10 3 5 10 12 Divisible by 5 Divisible by Divisible by 5, 5 and 10 10 and 100 25 310 500 105 690 1000 14 18 1 70 20 80 3 13 61 17 43 52 54 90 31 27 4 63 32 69 39 44 19 29 75 9 14 59 5 20 41 30 38 34 73 33 51 51 69 53 57 105 87 18 Number of people 63 8 17 34 29 77 32 71 43 59 49 62 79 17 Challenge No, 15 553 does not end in 5 or 0. 8 205 is odd. Numbers divisible by 2 and 10 must be even. 9 16 4 6 8 11 5 3 7 9 13 15 17 19 Correctly completed Carroll diagram with learners’ categories. 67 62 46 10 53 22 70 25 7 12 28 55 73 7 2 Odd 1 20 4 6 Less than 10 Bar chart showing how many pets each person has 16 14 12 10 8 6 4 a 300 and 600 b 50, 300, 350, 600, 650 c 50, 75, 300, 350, 600, 650, 675 2 0 0 1 2 3 Number of pets 4 10 17 a 9 b 4 b Bar chart Practice 20 6 a Venn diagram 7 a b Venn diagram, Carroll diagram Two from bar chart, pictogram and dot plot Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 8 13 a Odd 28 22 24 26 29 25 15 Time for Anna to get to school Multiple of 5 28 20 30 Clara should have curly hair and no glasses. 10 Answer depends on the data collected by learners. Learners should choose to represent the data in a bar chart, dot plot or pictogram. They should give the reason that the graph or chart they have chosen to represent their data shows the number of names in each group so each group can be easily compared. 11 There are no factors of 12 that are odd and not less than 10. 14 Correctly completed Carroll diagram. Number of minutes to get to school 27 7 1 3 6 11 9 19 5 13 8 4 17 15 2 16 12 14 18 10 Less than 20 9 b 23 21 Numbers 6, 10, 11, 14, 19, 20 circled. Number of birds Basil saw on each day 26 24 22 20 18 16 14 12 10 8 6 4 2 b c b 21 3 Day 4 5 6 Time for Carlos to get to school 4 2 1 2 3 Day 4 5 Both Daisy and Basil saw 10 birds on day 1. Daisy saw many more birds than Basil. In total Daisy saw 64 birds, but Basil only saw 31 birds. Learners might refer to Daisy and Basil being in different places, in different seasons, or experiencing different weather that might affect the number of birds. Challenge 12 a 2 8 0 a 1 10 Number of minutes to get to school Number of birds 0 a A Carroll diagram can be used to sort numbers, shapes or other items according to their properties. A pictogram is used to display data so that it can be more easily interpreted and compared. b c 20 18 16 14 12 10 8 6 4 2 0 1 2 3 Day 4 5 The same scale makes the data in the bar charts easier to compare. Anna and Carlos both took the longest time to get to school on day 5. Anna took longer to get to school than Carlos on every day. Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE d Learners might refer to Anna and Carlos living different distances from school or using different forms of transportation, for example walking or catching a bus. 9 Paula has 2 × 8 = 16 balloons and Milly has 4 × 16 = 64 balloons. 10 30 × 5 or 50 × 3 Challenge 17 Multiplication and division 11 821 × 9 = 7389 (921 × 8 = 7368) 12 40 × 5 = 200 but learners have recorded this as 20, which may indicate a place value error. Exercise 17.1 The correct answer is 3705. 13 80 × 4 = 320 or 40 × 8 = 320 Focus 14 7 (476 × 7 = 3332) 1 24 comics 2 78 tins 3 The 4 tens should be carried. The correct answer is 282. Yes, because 300 × 8 = 2400 Exercise 17.2 4 5 144 1 29 Either: 48 × 4 = 192 → 192 − 48 = 144 or 48 × 3 = 144 2 16 Practice 3 5 pencils; 7 cents 6 290 4 No. 7 a 5 50 ÷ 6 = 8 r2 so Conrad needs 9 boxes to hold all the eggs. 15 trays 15 Yes and three examples, such as: Using 12, 13 and 14: and 13 × 3 = 39 Focus 19 133 7 b Practice 76 28 6 2 photos 7 1 and 24, 2 and 12, 3 and 8, 4 and 6 (numbers in either order). 8 True False 70 ÷ 7 = 10 63 ÷ 7 = 9 63 ÷ 9 = 7 45 ÷ 5 = 9 25 ÷ 4 = 5 76 ÷ 9 = 8 84 ÷ 8 = 11 29 ÷ 3 = 9 76 ÷ 9 = 8 4 17 51 136 9 3 8 24 12 + 13 + 14 = 39 No, the teacher needs 16 more pens. 24 × 6 = 144 160 – 144 = 16 or 25 × 6 = 150 which is less than 160 or any other valid explanation. 10 9 8 Ollie is correct. Erik has forgotten to add in the 1 hundred that has been carried. 22 Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE Challenge 3 11 1 and 48, 2 and 24, 3 and 16, 4 and 12, 6 and 8 (numbers in either order). y-axis (2, 6) 6 12 75 ÷ 5 = 15 but all the other answers are 12. Accept any other valid choice provided it is clearly explained. 5 13 < 3 < (4, 4) 4 (1, 2) < 2 14 (5, 3) 96 1 8 (3, 0) 12 0 0 4 2 4 4 5 6 x-axis 6 5 4 3 Exercise 18.1 2 Focus 1 N 0 0 NW 1 2 3 4 5 6 x-axis NE W Pentagon E SW SE Practice 5 23 3 y-axis 18 Position, direction and movement 2 2 6 15 28 rhombuses. (She makes 56 ÷ 4 = 14 fish and each fish uses 2 rhombuses.) 1 1 i S (South) S ii SW (South-west) 1. North-east iii NE (North-east) 2. East b NW (North-west) 3. South c SE (South-east) 4. South-west 5. South-east 6 a quadrant Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 7 a 10 y-axis y-axis 6 6 5 5 4 4 3 3 2 2 1 0 1 0 2 1 3 4 5 6 x-axis 0 0 b Rectangle 1 2 3 4 5 6 x-axis (5, 4) Exercise 18.2 Challenge 8 Focus N 0 degrees NW 315 degrees NE 45 degrees W 270 degrees 1 E 90 degrees SW 225 degrees SE 135 degrees S 180 degrees 9 y-axis (5, 6) 6 5 (4, 5) 4 2 (5, 4) 3 2 (2, 2) 1 (1, 0) 0 0 24 1 2 3 4 5 6 x-axis Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE 3 a (1, 4) (3, 6) (5, 4) in any order. b y-axis 5 6 5 4 3 2 1 0 0 2 3 4 5 c (1, 4) (3, 2) (5, 4) in any order. d Square Practice 4 1 6 x-axis 6 7 a (2, 3) (2, 6) (5, 3) (5, 6) in any order. b Rectangle c Shape reflected to give a rectangle. More than one solution. One possible solution is: y-axis 6 5 4 3 2 1 0 0 25 1 2 3 4 5 6 x-axis Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com) lOMoARcPSD|42896089 CAMBRIDGE PRIMARY MATHEMATICS 4: TEACHER’S RESOURCE Challenge c y-axis 8 6 5 4 3 2 1 0 0 1 2 3 4 6 x-axis 5 11 More than one solution. One possible solution is: y-axis 9 6 5 4 3 2 1 0 0 10 a b 26 1 2 3 4 5 6 x-axis Octagon (3, 4) (5, 4) (6, 3) (4, 2) (1, 3) in any order. Cambridge Primary Mathematics 4 – Wood & Low © Cambridge University Press 2021 Downloaded by fion kin (fionkin106@gmail.com)