MATH IN MY WORLD key 5

NGUYỄN TRƯỜNG GIANG PHẠM TRÍ ĐỨC - NGUYỄN TRUNG HIẾU Answer key... AB is the height; AC is the base b.. HA is the height; NO is the base 2... AD and BC are two bases; AB and CD are two l

NGUYỄN TRƯỜNG GIANG PHẠM TRÍ ĐỨC - NGUYỄN TRUNG HIẾU

Answer key

LET’S GET STARTED

Page 6

1 b

2 b

3 c

4 a

5 b

6 c

LET’S PRACTICE

Page 8

1 10,675; 5,768; 2,955; 13,056

2 a 13,743;

b 3,920

LET’S TRY

Page 9 &10

1 The answer is 9,750 m2

2 187; 165; the answer is 352 (students)

MATH IN MY WORLD

Page 10

The answer is 1,250 (pages)

Unit 1

Page 11

1 1,462; 16,692; 47,311; 1,452

2 234; 2,340; 1,794; 17,940

3 The answer is 1,800 (times)

4 273,000; 322,500; the answer is 595,500 (vnd)

Unit 2

LET’S PRACTICE

Page 12

1 372; 12; 280; 7

2 a 258;

b 207

LET’S TRY

Page 13

1 The answer is 105 (m)

2 The answer is 16 (sets)

MATH IN MY WORLD

Page 14

The answer is 42 (m2)

Unit 3

Page 15

1 107; 234; 315; 57.

2 6,240; the answer is 104 (packages)

3 38,400 m; 75 mins; 0.512 km/min

Unit 4

LET’S PRACTICE

Page 18

2 40 cm2; 1,400 cm2; 8,820 cm2

LET’S TRY

Page 18 & 19

1 The answer is 1,000 (dm2)

2 9 m; the answer is 108 (m2)

MATH IN MY WORLD

Page 19

6 parallelograms

Unit 5

LET’S PRACTICE

Page 20 & 21

1 Four hundred twenty nine square kilometer; fifty one thousand thirty-four

square kilometer; 100,300 km2; 67,000,000 km2

2 a 1,000,000 m2;

b 100 cm2;

c 5.25 m2;

d 1 km2;

e 8,000,000 m2; f 4.05 m2

LET’S TRY

Page 21 & 22

1 3.6 km; 16.2 km2

2 1 km; the answer is 3 km2

MATH IN MY WOLRD

Page 22

1 C;

2 C

Unit 6

LET’S PRACTICE

Page 23 & 24

1 a ; b ; c

2 ; ; ;

3 ; ; ;

LET’S TRY

Page 24

MATH IN MY WORLD

less than 1: ; equal to 1: ; greater than 1:

Unit 7

LET’S PRACTICE

Page 26 & 27

1 a ; b ;

2 a = ; b = =

3 ; ; ;

LET’S TRY

Page 27

1

2 = ; =

MATH IN MY WORLD

‘a’ is the correct answer

Unit 8

Page 28

1 b

2 c

3 b

4 b

6 a 5,000,000 m2;

b 6 km2;

c 52.64 m2;

d 1,000 dm2

Page 29

7 a 171 cm2;

b 206 cm2

8 a 25 m;

Review 1

LET’S PRACTICE

Page 32

1 a and ;

b and

2 a ; and ;

b ; and

LET’S TRY

1 and ;

2 and

MATH IN MY WORLD

Page 33

Unit 9

LET’S PRACTICE

Page 35

LET’S TRY

Page 35 & 36

1 The answer is (m)

2 (m) and 2 (m)

MATH IN MY WOLRD

Page 36

a and ;

b and

Unit 10

LET’S PRACTICE

Page 38

LET’S TRY

1 64 (m);

2 288 (m); 5,120 (m2)

MATH IN MY WOLRD

Page 39

m2; m2

Unit 11

Page 40

1 a. ; b ; c ; d

2 a ; b 1

3 4 (m)

4

Page 41

5 a (km2); b (km2)

Unit 12

LET’S PRACTICE

Page 43 & 44

1 a AB is the height; AC is the base

b HA is the height; NO is the base

2 a 0.216 cm2; 2.16 m2

LET’S TRY

Page 44

2.7 m; 4.86 m2

Unit 13

Unit 14

LET’S PRACTICE

Page 45 & 46

1 a AD and BC are two bases; AB and CD are two lateral sides; HB is the height

b MN and PQ are two bases; PM and QN are two lateral sides; PM is also the height

2 a 6.9 cm2; b 9,660 cm2

LET’S TRY

Page 46 & 47

Page 47

2 a 36 (m);

b 10,125 (kg)

LET’S PRACTICE

Page 48

2 a 7.85 cm;

b 8.164 cm

LET’S TRY

Page 49

1 282.6 cm

2 18.84 cm; 37.68 cm.

Unit 15

LET’S PRACTICE

Page 50

1 a 4.5216 cm2;

b 0.5 dm; 0.785 dm2

2 1.5 m; 7.065 m2

LET’S TRY

Page 51

1 3 cm; 28.26 cm2

2 36 cm2; 7.74 cm2

MATH IN MY WORLD

Page 51 & 52

1.5386 m2; 1 m; 3.14 m2; 1.6014 m2

Unit 16

Page 53

2

3 (m2)

Page 54

5 C = 3.768 dm, S = 1.1304 dm2

6 The difference is 125.6 cm

Page 55

Review 2