SChand New Learning Composite Mathematics Class 6 Chapter 2 Whole Numbers Exercise 2E

Exercise 2E

Question 1

(a) 8, 13, 18, 23, 28, 33, 38, 43

∴ Increase each term by 5.

(b) 56, 54, 52, 50, 48, 46

∴ Decrease each term by 2.

(c) 7, 14, 28, 56, 112, 224

∴ Multiply the previous number by 2.

(d) 25, 24, 23, 22, 21, 20

∴ Each term decreases by 1.

(e) 5, 10, 15, 20, 25, 30

∴ Each term increasing by 5.

(f) 100, 94, 88, 82, 76, 70

∴ Each term decreases by 6.

(g) 15 ml, 25 ml, 35 ml, 45 ml, 55 ml, 65 ml

∴ Increases each term by 10 ml.

(h) 1, 4, 9, 16, 25, 36, 49

∴ The are square numbers of consecutive natural number.

(j) 0, 1, 3, 6, 10, 15, 21, 28, 36, 45

∴ First term increased by 1, 2^nd term by 2, 3^rd term by 3 and so on.

(k) 0, 3, 8, 15, 24, 35, 48, 63

∴ First term increased by 3, 2^nd term by 5, 3^rd term by 7, 4^th term by 9, and so on.

(l) 1, 3, 9, 27, 81, 243, 729

∴ Multiply the previous number by 3.

(m) 101, 202, 303, 404, 505, 606

∴ Each term increases by 101

(n) 10:20 P.M, 10:10 P.M, 10:00 PM, 9:50 PM, 9:40 PM

∴ Each term decreases by 10 minutes.

(o) 14, 28, 42, 56, 70, 84

∴ Each term increases by 14

(p) 18, 36, 72, 144, 288, 576

∴ Multiply the previous term by 2.

(q) 90, 81, 72, 63, 54, 45

∴ Each term decreases by 9.

Question 2

(a)

$2\xrightarrow{+7}9\xrightarrow{-2}7\xrightarrow{+7}14\xrightarrow{-2}12\xrightarrow{+7}19\xrightarrow{-2}17$

∴Add 7 to one term and then subtract 2 from the next term.

(b)

$50\xrightarrow{-10}40\xrightarrow{+3}43\xrightarrow{-10}33\xrightarrow{+3}36\xrightarrow{-10}26\xrightarrow{+3}29$

∴Subtract 10 from one term and then add 3 to the next term.

(c)

$60\xrightarrow{-4}56\xrightarrow{+5}61\xrightarrow{-4}57\xrightarrow{+5}62\xrightarrow{-4}58\xrightarrow{+5}63\xrightarrow{-4}59\xrightarrow{+5}64$

∴Subtract 4 from one term and then add 5 to next term.

(d)

$100\xrightarrow{÷2}50\xrightarrow{×4}200\xrightarrow{÷2}100\xrightarrow{×4}400\xrightarrow{÷2}200$

∴Divide by 2 from one term and then multiply by 4 to the next term.

(e)

$2\xrightarrow{×3}6\xrightarrow{-1}5\xrightarrow{×3}15\xrightarrow{-1}14\xrightarrow{×3}42\xrightarrow{-1}41\xrightarrow{×3}123$

∴Multiplying by 3 to the one term then decrease 1 from the next term

(f)

$80\xrightarrow{÷10}8\xrightarrow{×5}40\xrightarrow{÷10}4\xrightarrow{×5}20\xrightarrow{÷10}2\xrightarrow{×5}10\xrightarrow{÷10}1$

∴Divide by 10 to the one term then multiplying 2 to the next term.

Question 3

1×9+1=10

12×9+2=110

123×9+3=110

1234×9+4=11110

12345×9+5=111110

SChand New Learning Composite Mathematics Class 6 Chapter 2 Whole Numbers Exercise 2D

Exercise 2D

Question 1

(a) Parentheses

(b) Parentheses

(c) Multiplication

(d) Addition

(e) Division

(f) Parentheses

Question 2

(a) 27 – 11 + 4

= 16 + 4

= 20

(b) (28 – 8) ÷ 4

= 20 ÷ 4

= 5

(c) 136 – 100 ÷ 5

= 136 – 20

= 116

(d) 80 – 35 x 2

= 80 – 70

= 10

(e) 20 + 15 ÷ 3 – 8

= 20 + 5 – 8

= 17

(f) 14 x (17 – 7) + 5

= 14 x 10 + 5

= 140 + 5

= 145

(g) 54 ÷ 9 + 3 x 5

= 6 + 3 x 5

= 6 + 15

= 21

(h) 60 – 8 x 12 ÷ 3

= 60 – 8 x 4

= 60 – 32

= 28

(i) 15 ÷ 3 x 5

= 5 x 5

= 25

(j) 18 ÷ (6 ÷ 3)

= 18 ÷ 2

= 9

(k) (20 ÷ 4) ÷ 5

= 5 ÷ 5

= 1

(l) 4 x 5 + 8 – 7

= 20 + 4 – 7

= 24 – 7

= 17

(m) 19 – 15 ÷ 5 – 16

= 19 – 3 – 16

= 16 – 16

= 0

(n) 8 x (7 – 2) ÷ 5 – 8

= 8 x 5 ÷ 5 – 8

= 8 x 1 – 8

= 8 – 8

= 0

(o) 72 ÷ (9 + 0 x 8) ÷ 8

= 72 ÷ (9 + 0) ÷ 8

= 72 ÷ 9 ÷ 8

= 8 ÷ 8

= 1

Question 3

(a) 24 – (8 ÷ 4 x 2) = 20

(b) 24 – 8 ÷ (4 x 2) = 23

(c) (24 – 8) ÷ 4 x 2 = 8

(d) (24 – 8 ÷ 4) x 2 = 44

(e) (7 + 2) x 6 – (4 -3) = 53

(f) 16 x (3 -2) ÷ 4 = 4

(g) 8 x (0 + 4) – 5 = 27

(h) 26 ÷ (5 + 8) x 7 = 14

Question 4

(a) 7 x 4 – 3

= 28 – 3

= 25

7 x (4 – 3)

= 7 x 1

= 7

7 x 4 – 3 > 7 x (4 – 3)

(b) 60 ÷ 5 x 4

= 12 x 4

= 48

60 ÷ (5 x 4)

= 60 ÷ 20

= 3

60 ÷ 5 x 4 > 60 ÷ (5 x 4)

(c) (8 + 12) ÷ 4

= 20 ÷ 4

= 50

8 + 12 ÷ 4

= 8 + 3

= 11

(8 + 12) ÷ 4 < 8 + 12 ÷ 4

(d) 23 – 18 + 7

= 5 + 7

= 12

15 ÷ 3 + 7

= 5 + 7

= 12

23 – 18  + 7 = 15 ÷ 3 + 7

Question 5

(a) (1025 ÷ 25) ÷ (205 ÷ 5)

= 41 ÷ 41

= 1

(b) (1500 ÷ 1500) x (165 ÷ 165)

= 1 x 1

= 1

SChand New Learning Composite Mathematics Class 6 Chapter 2 Whole Numbers Exercise 2C

 Exercise 2C

Question 1

SChand New Learning Composite Mathematics Class 6 Chapter 2 Whole Numbers Exercise 2B

 Exercise 2B

Question 1

(a) 8396 x 1 = 8396

(b) 64937 x 0 = 0

(c) 45 x 7 = 7 x 45

(d) (7 x 4) x 3= 7 x (4 x 3)

(e) 194 x 23 = 194 x (20 + 3)

(f) 89 x 302 = 89 x 300 + 89 x 2

(g) 57 x 29 = 57 x 20 + 57 x 5 + 57 x 4

(h) 12(8 – 5) = (12 x 8) – (12 x 5)

Question 2

(a) Identity property

(b) Property of zero

(c) Commutative Property

(d) Commutative Property

(e) Distributive Over Addition

(f) Associative Property.

Question 3

(a) 50 x 27 x 2

= (50 x 2) x 27 [Associative Property]

= 100 x 27

= 2700

(b ) 4 x (9 x 25)

= 4 x 225

= 900

(c) 25 x 39 x 8

= (25 x 8) x 39 [Associative Property]

= 200 x 39

= 7800

(d) 625 x 20 x 8 x 50

= (625 x 20) x (8 x 50) [Group the factor to make calculation easy]

= 12500  x 400

= 50,00,000

(e) 16 x 250 x 125 x 2

= (16 x 250) x (125 x 2) [Group the factor to make calculation easy]

= 4000 x 250

= 1,0,00,000

Question 4

(a) 79328 x 93 + 7 x 79328

= 79328 x (93 +7) [ Distributive Property over addition]

= 79328 x 100

= 7932800

(b) 8057 x 59 + 8057 x 25 + 8057 x 16

= 8057 x (59 + 25 + 16) [Distributive Property over addition]

= 8057 x 100

= 805700

Question 5

(a) 9 x 15

= (10 – 1) x 15

= (10 x 15) – (1 x 15)

= 150 – 15

= 135

(b) 82 x 103

= 82 x (100 + 3)

= (82 x 100) + (82 x 3)

= 8200 + 246

= 8446

(c) 7 x 124

= 7 x (100 + 24)

= (7 x 100) + (7 x 24)

= 700 + 168

= 868

(d) 3807 x 8

= (3800 + 7) x 8

= (3800 x 8) + (7 x 8)

= 30400 + 56

= 30456

(e) 258 x 1008

= 258 x (1000 + 8)

= (258 x 1000) + (258 x 8)

= 258000 + 2064

= 260064

(f) 869 x 10005

= 869 x (10000 + 5)

= (869 x 10000) + (869 x 5)

= 8690000 + 4345

= 8694345

SChand New Learning Composite Mathematics Class 6 Chapter 2 Whole Numbers Exercise 2A

Exercise 2A

Question 1

(a) 5 + 9 = 14

9 + 5 = 14

Commutative Property.

Question 2

495 – 0 = 495

Property of zero.

(c) 7+(4+9) = 7 + 13 = 20

(7 + 4) + 9 = 11 + 9 = 20

Associative property.

Question 3

(a) Commutative property.

(b) Additive Property.

(c) Associative Property.

(d) Commutative Property.

Question 6

(a) 8 + 23 + 2 = 23 + 8 + 2 [Commutative property]

= 23 + (8 + 2) [Associative Property]

= 23 + 10

= 33

(b) 17 + 29 + 3 = 29 + 17 + 3 [Commutative Property]

= 29 + (17 + 3) [Associative Property]

= 29 + 20

= 49

(c) 16 + 47 + 14 = 16 + 14 + 47 [Commutative Property]

16 + (14 + 47) [Associative Property]

= 16 + 61

= 77

(d) 33 + 48 + 7 = 7 + 33 + 48 [Commutative Property]

= 7 + (33 + 48)

= 7 + 81

= 88

(e) 20 + (63 + 80)

= 20 + 143

= 163

(f) 8 + 13 + 7 + 12 = 8 + 7 13 + 12 [Commutative]

= (8 + 7) + (13 + 12) [Associative]

= 15 + 25

Question 7

(a) 869 + 73 + 237 + 31

= 869 + 31 + 73 + 237 [Commutative]

= (869 + 31) + (73 + 237) [Associative]

= 900 + 310

= 1210

(b) 916 + 425 + 584 + 315

= 916 + 584 + 425 + 315 [Commutative]

= (916 + 584) + (425 + 315) [Associative]

= 1500 + 740

= 2240

(c) 1756 + 683 + 1244 + 517

= (1756 + 1244) + (683 + 517) [Commutative]

= 3000 + 1200 [Associative]

= 4200