Maths Wiz Solutions Class 7 Chapter 2 Whole Numbers
Welcome to NCTB Solutions. Here with this post we are going to help 7th class students for the Solutions of Maths Wiz Class 7 Math Book, Chapter 2, Whole Numbers. Here students can easily find step by step solutions of all the problems for Whole Numbers, Self Practice 2A, 2B, 2C, 2D and 2E Also here our mathematics teacher’s are solved all the problems with easily understandable methods with proper guidance so that all the students can understand easily. Here in this post students will get chapter 2 solutions. Here in this post all the solutions are based on ICSE latest Syllabus.
Whole Numbers Self Practice 2A Solution :
Question no – (1)
Solution :
(a) 5 + 9 = 14
= 9 + 5 = 14
= Commutative.
(b) 495 – 0 = 495
= Property of Zero
(c) 7 + (4 + 9) = 20
= (7 + 4) + 9 = 20
= Associative
Question no – (2)
Solution :
(a) 19 + 25 = 25 + 19
= (Commutative properties)
(b) 856 + 0 = 856
= (Property of Zero)
(c) (23 + 15) + 17 = (23 + 17) 15
= (Associative)
(d) 0 + 15730 = 15730 + 0
= (Commutative properties)
Question no – (3)
Solution :
(a) 375 + __ = 125 + 375
= 375 + 125 = 125 + 375
= Commutative
(b) 0 + 307 = __
= 0 + 307 = 307
= Property of Zero
(c) 19000 + _ = 19000
= 19000 + 0 = 19000
= Property of Zero
(d) 33 + (307 + 58) (33 + _) + 58
= 33 + (307 + 58) (33 + 307) + 58
= Associative
Question no – (4)
Solution :
(a) Identity property
Example : 39 + 0 = 39
(b) Commutative property
Example : 7 – 4 = 4 – 7
(c) Associative property
Example : 5 + (2 + 2) = (5 + 2) + 2
Question no – (5)
Solution :
(a) 15 + 0 = 0
= Statement is False
(b) 7 + 86 = 86 + 7
= Statement is True
(c) (25 + 7) + 9 = (25 + 9) + 7
= Statement is True
(d) 25 – 17 = 17 – 25
= Statement is False
(e) 587 – 0 = 587
= Statement is True
(f) 95 – 0 = 0 – 95
= Statement is False
(g) (24 – 7) – 5 = 24 – (7 – 5)
= Statement is False
(h) 78 – 80 is a whole number
= Statement is False
Question no – (6)
Solution :
(a) 8 + 23 + 2
= 33…(Simplified)
(b) 17 + 29 + 3
= 49…(Simplified)
(c) 16 + 47 + 14
= 77…(Simplified)
(d) 33 + 48 + 7
= 88…(Simplified)
(e) 20 + (63 + 80)
= 163…(Simplified)
(f) 8 + 13 + 7 + 12
= 40…(Simplified)
Question no – (7)
Solution :
(a) 863 + 73 + 237 + 31
= 1210
(b) 916 + 425 + 584 + 315
= 2240
(c) 1756 + 683 + 1244 + 517
= 4200
Whole Numbers Self Practice 2B Solution :
Question no – (1)
Solution :
(a) 8396 × 1 = 8396
(b) 64937 × 0 = 0
(c) 45 × 7 = 7 × 45
(d) (7 × 4) × 3 = 7 × (4 × 3)
(e) 194 × 23 = 194 (20 + 3)
(f) 89 × 302 = 89 × 300 + 89 × 0
(g) 57 × 29 = 57 × 20 + 57 × 5 + 57 × 4
(h) 12 (8 – 5) = (12 × 8) – (12 × 5)
Question no – (2)
Solution :
(a) 37 × 1 = 37 = Here, Identity Property is used.
(b) 0 × 958 = 0 = Here, property of zero is used.
(c) 28 × 17 = 17 × 28 = Here, commutative property is used.
(d) 2 × 19× 5 = 19 × 2 × 5 = Here, commutative property is used.
(e) 1538 × 17 + 1538 × 3 = 1538 × (17 + 3) = Here, Distributive over addition property is used.
(f) (724 × 16) × 25 = 724 × (16 × 25) = Here, Associative property is used.
Question no – (3)
Solution :
(a) 50 × 27 × 2
= 2700
(b) 4 × (9 × 25)
= 900
(c) 25 × 39 × 8
= 7800
(d) 625 × 20 × 8 × 50
= 50, 00, 000
(e) 16 × 250 × 125 × 2
= 10, 00, 000
Question no – (4)
Solution :
(a) 79328 × 7 × 79328
= 79328 (93 + 7)
= 79328 × 100
= 7932800
(b) 8057 × 59 + 8057 × 25 + 8057 × 16
= 8057 (59 + 25 +16)
= 8057 × 100
= 805700
Question no – (5)
Solution :
(a) 9 × 15
= 135
(b) 82 × 103
= 8446
(c) 7 × 124
= 868
(d) 3807 × 8
= 30456
(e) 258 × 1008
= 260064
(f) 869 × 10005
= 8694345
Whole Numbers Self Practice 2C Solution :
Question no – (1)
Solution :
(a) 5973 ÷ 1
= 5973
∴ The value will be 5973
(b) 0 ÷ 675
= 0
Hence, the value will be 0
(c) 9087 ÷ 9087
= 1
So, the value will be 1
(d) 100 – (593 ÷ 593)
= 100 – 1
= 99
Hence, the value will be 99
(e) 500 ÷ (98 – 48)
= 500 ÷ 50
= 10
Hence, the value will be 10
(f) 0 ÷ 9 = (880 ÷ 880)
= 0 ÷ 1
= 0
∴ The value will be 0
(g) 2345 ÷ (2345 ÷ 2345)
= 2345 ÷ 1
= 2345
∴ The value will be 2345
(h) 786 ÷ 786
= 1
∴ The value will be 1
(i) 859 ÷ 859
= 1
∴ The value will be 1
(j) (790 – 790) ÷ (790 ÷ 1)
= 0 ÷ 790
= 0
Therefore, the value will be 0
Question no – (2)
Solution :
(a) 26 ÷ 26 = 26
= This statement is False.
(b) 9084 ÷ 1 = 9084
= This statement is True.
(c) 8 ÷ 3 is a whole number
= This statement is False.
(d) 7039 ÷ 7039 = 1
= This statement is True.
(e) If a is any whole number, then a/0 = 0
= This statement is False.
Question no – (3)
Solution :
(a) 0 ÷ a = 0
= 0 ÷ 0 = 0
∴ Here, a = 1
(b) 62 ÷ 62 = n
= 62 ÷ 62 = 1
∴ Here, n = 1
(c) a ÷ 19 = 0
∴ Here, a = 0
(d) m ÷ 876 = 0
= 0 ÷ 876 = 0
∴ Here, m = 0
(e) 0 ÷ 2058 = x
= 0 ÷ 2058 = 0
∴ Here, x = 0
(f) (85 – 24) ÷ n = 3
= (85 – 24) ÷ 17 = 3
n = 17
(g) (81 ÷ 9) ÷ n = 9
= (81 ÷ 9) ÷ 1 = 9
= n = 1
(h) 2958 ÷ 2958 + 0 ÷ 2958 = n
= 2958 ÷ 2958 + 0 ÷ 2958 = 1
= n = 1
Question no – (4)
Solution :
(a) 98 × 12 – 78 × 12
= 12 (98 – 78)
= 12 × 20
= 240
(b) 10000 ÷ 100 ÷ 100
= 1000 ÷ (100 ÷ 100)
= 1000 ÷ 1
= 1000
Whole Numbers Self Practice 2D Solution :
Question no – (1)
Solution :
(a) (6 + 7) × 5
= 13 × 5
= 65
∴ “Parentheses” should be done first.
(b) 9 ÷ (3 – 2)
= 9 ÷ 1
= 9
∴ “Parentheses” should be done first.
(c) 6 + 2 × 7
= + 14
= 20
∴ “Multiplication” should be done first.
(d) 15 – 8 + 4
= 15 – 12 = 3
∴ “Addition” should be done first.
(e) 8 ÷ 4 + 6
= 2 + 6
= 8
∴ “Division” should be done first.
(f) 11 + 14 ÷ (6 + 1)
= 11 + 14 ÷ 5
= 25 ÷ 5
= 5
∴ “Parentheses” should be done first.
Question no – (2)
Solution :
(a) 27 – 11 + 4
= 16 + 4
= 20 …(Simplified)
(b) (28 – 8) ÷ 4
= 20 ÷ 4
= 5 …(Simplified)
(c) 136 – 100 ÷ 5
= 136 – 20
= 116 …(Simplified)
(d) 80 – 35 × 2
= 80 – 70
= 10 …(Simplified)
(e) 20 + 15 ÷ 3 – 8
= 20 + 5 – 8
= 25 – 8
= 17 …(Simplified)
(f) 14 × (17 – 7) + 5
= 14 × 10 + 5
= 140 + 5
= 145…(Simplified)
(g) 54 ÷ 9 + 3 × 5
= 6 + 15
= 21 …(Simplified)
(h) 60 – 8 × 12 ÷ 3
= 60 – 8 × 4
= 60 – 32
= 28 …(Simplified)
(i) 15 ÷ 3 × 5
= 5 × 5
= 25 …(Simplified)
(j) 18 ÷ (6 ÷ 3)
= 18 ÷ 2
= 9 …(Simplified)
(k) (20 ÷ 4) ÷ 5
= 5 ÷ 5
= 1 …(Simplified)
(l) 4 × 5 + 8 ÷ 2 – 7
= 20 + 4 – 7
= 20 – 3
= 17 …(Simplified)
(m) 19 – 15 ÷ 5 – 16
= 19 – 3 – 16
= 19 – 19
= 0 …(Simplified)
(n) 8 × (7 – 2) ÷ 5 – 8
= 8 × 5 ÷ 5 – 8
= 8 × 1 – 8
= 0 …(Simplified)
(o) 72 ÷ (9 + 0 × 8) ÷ 8
= 72 ÷ (9 + 0) ÷ 8
= 72 ÷ 9 ÷8
= 8 ÷ 8
= 1 …(Simplified)
Question no – (3)
Solution :
(a) 24 – 8 ÷ 4 × 2 = 20
= 24 – (8 ÷ 4 × 2)
= 20
(b) 24 – 8 ÷ 4 × 2 = 23
= 24 – 8 ÷ (4 × 2)
= 23
(c) 24 – 8 ÷ 4 × 2 = 8
= (24 – 8) ÷ 4 × 2
= 8
(d) (24 – 8) ÷ 4 × 2 = 44
= (24 – 8 ÷ 4) × 2
= 44
(e) 7 + 2 × 6 – 4 – 3 = 53
= (7 + 2) × 6 – 4 – 3
= 53
(f) 16 × 3 – 2 ÷ 4 = 4
= 16 × (3 – 2) ÷ 4)
= 4
(g) 8 × 0 + 4 – 5 = 27
= 8 × (0 + 4) – 5
= 27
(h) 26 ÷ (5 + 8) × 7 = 14
= 26 ÷ 5 + 8 × 7
= 3.5
Question no – (4)
Solution :
(a) 7 × 4 – 3 __ 7 × (4 – 3)
= 7 × 4 – 3 (>) 7 × (4 – 3)
(b) 60 ÷ 5 × 4 __ 60 ÷ (5 × 4)
= 60 ÷ 5 × 4 (>) 60 ÷ (5 × 4)
(c) (8 + 12) ÷ 4 __ 8 + 12 ÷ 4
= (8 + 12) ÷ 4 (<) 8 + 12 ÷ 4
(d) 23 – 18 + 7 __ 15 ÷ 3 + 7
= 23 – 18 + 7 (=) 15 ÷ 3 + 7
Question no – (5)
Solution :
(a) (1025 ÷ 25) ÷ (205 ÷ 5)
= 41 ÷ 41
= 1
(b) (1500 ÷ 1500) × (165 ÷ 165)
= 1 × 1
= 1
Whole Numbers Self Practice 2E Solution :
Question no – (1)
Solution :
(a) 8, 13, 18, 23, 28, 33, ….
= Increase 1 by ‘5’ =
= 8, 13, 18, 23, 28, 33
(b) 56, 54, 52, 50, …..
= Decrease by ‘2’
= 56, 54, 52, 50, 48, 46,
(c) 7, 14, 28, 56, …..
= Multiplying the previous run by 2,
= 7, 14, 28, 56, 112, 224
(d) 25, 24, 23, 22, …..
= Decrease by ‘1’,
= 25, 24, 23, 22, 21, 20
(e) 5, 10, 15, 20, …..
= Increase by ‘5’
= 5, 10, 15, 20, 25, 30
(f) 100, 94, 88, 82, ……
= decrease by ‘6’
= 100, 94, 88, 82, 76, 70
(g) 15 mL, 25 mL, 35 mL, 45 mL, ……
= increase by ‘10’
= 15 mL, 25 mL, 35 mL, 45 mL, 55 ml, 65 ml.
(h) 1, 4, 9, 16, 25, …..
= Square number of consecutive natural number
= 1, 4, 9, 16, 25, 36, 49
(i) 1, 8, 27, 64, 125, ……
= Cube number of consecutive natural number
= 1, 8, 27, 64, 125, 243, 729
(j) 0, 1, 3, 6, 10, 15, 21, 28, …….
= 1st terms increase by 1, 2nd term increase by 2 and so on,
= 0, 1, 3, 6, 10, 15, 21, 28, 36, 45
(k) 1, 8, 27, 64, 125, ……
= Cube number of consecutive natural number
= 1, 8, 27, 64, 125, 243, 729
(l) 1, 3, 9, 27, 81, …..
= multiply by perfidious term,
= 1, 3, 9, 27, 21, 81, 243, 729
(m) 101, 202, 303, 404, ……
= increase by 101,
= 101, 202, 303, 404, 505, 606
(n) 10 : 20 p.m., 10 : 10 p.m., 10 : 00 p.m…..
= decrease by 10 min,
= 10 : 20 p.m., 10 : 10 p.m., 10 : 00 p.m., 9 : p.m., 9 : 40 p.m.
(o) 14, 28, 42, 56, …..
= Increase by 14,
= 14, 28, 42, 56, 70, 84
(p) 18, 36, 72, 144, …..
= multiply the previous tern by 2,
= 18, 36, 72, 144, 288, 576
(q) 90, 81, 72, 63, …..
= decrease by 9,
= 90, 81, 72, 81, 54, 45
Question no – (2)
Solution :
(a) 2, 9, 7, 14, 12, 24, 17
(b) 50, 40, 43, 33, 23, 26, 36
(c) 60, 56, 61, 57, 62, 58, 63, 59, 64
(d) 100, 50, 200, 100, 400, 200
(e) 2, 6, 5, 15, 14, 42, 41, 123.
(f) 80, 8, 40, 4, 20, 2, 10, 1,
Question no – (3)
Solution :
1 × 9 + 1 = 10
12 × 9 + 2 = 110
123 × 9 + 3 = 1110
1234 × 9 + 4 = 11110
1234 × 9 + 4 = 111110
Next Chapter Solution :
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