
This page provides NCERT Class 7 Maths Chapter 1 solutions, exercise-wise answers, important integer rules, solved examples and extra practice questions. It is useful for homework, revision and exam preparation.
Edition note: This page covers the earlier NCERT Class 7 Maths chapter titled Integers, which matches the chapter and search intent represented by this URL. In the current 2026-27 NCERT Ganita Prakash textbook, Chapter 1 is Large Numbers Around Us, while integer operations are covered in Chapter 10, Operations with Integers.
|
Topic |
What you learn |
|
Integers |
Positive integers, negative integers and zero |
|
Number line |
Representing and comparing integers |
|
Addition |
Adding integers with the same or different signs |
|
Subtraction |
Subtracting an integer by adding its opposite |
|
Multiplication |
Sign rules and properties of multiplication |
|
Division |
Sign rules and properties of division |
|
Word problems |
Temperature, profit and loss, elevation and scores |
The older NCERT chapter is divided into four exercises. Each exercise focuses on a different part of integer operations.
The temperatures shown on the number line are:
(a) Temperature difference between the hottest and coldest places
Hottest temperature = 22°C
Coldest temperature = -8°C
22 - (-8) = 22 + 8 = 30°C
Answer: 30°C
(b) Temperature difference between Lahulspiti and Srinagar
-2 - (-8) = -2 + 8 = 6°C
Answer: 6°C
(c) Temperature at Srinagar and Shimla taken together
-2 + 5 = 3°C
Since 3°C is less than 5°C but greater than -2°C, the combined temperature is less than Shimla's temperature but not less than Srinagar's temperature.
Jack's scores are:
25, -5, -10, 15 and 10
Total score:
25 + (-5) + (-10) + 15 + 10
= 25 - 5 - 10 + 15 + 10
= 35
Answer: Jack's total score is 35.
Monday temperature = -5°C
Tuesday:
-5 - 2 = -7°C
Wednesday:
-7 + 4 = -3°C
Answer:
Height of plane = 5000 m
Depth of submarine = -1200 m
Vertical distance:
5000 - (-1200)
= 5000 + 1200
= 6200 m
Answer: 6200 m
Deposit = +₹2000
Withdrawal = -₹1642
Balance:
2000 + (-1642) = ₹358
Answer: The balance is ₹358.
East is represented by a positive integer.
Therefore, west is represented by a negative integer.
Rita travels:
20 km east and 30 km west.
Final position from A:
20 + (-30) = -10 km
Answer: Rita is 10 km west of point A, represented by -10 km.
A magic square has the same sum in every row, column and diagonal.
For the first square, one diagonal does not have the same sum as the other rows, columns and diagonal.
Therefore, it is not a magic square.
For the second square, every row, column and diagonal has the sum -9.
Answer: The second square is a magic square.
(i) a = 21, b = 18
LHS:
21 - (-18) = 21 + 18 = 39
RHS:
21 + 18 = 39
Therefore:
LHS = RHS
The identity is verified.
The same method gives:
(a)
(-8) + (-4) = -12
(-8) - (-4) = -4
Therefore:
-12 < -4
Answer: <
(b)
(-3) + 7 - 19 = -15
15 - 8 + (-9) = -2
Therefore:
-15 < -2
Answer: <
(c)
23 - 41 + 11 = -7
23 - 41 - 11 = -29
Therefore:
-7 > -29
Answer: >
(d)
39 + (-24) - 15 = 0
36 + (-52) - (-36) = 20
Therefore:
0 < 20
Answer: <
(e)
-231 + 79 + 51 = -101
-399 + 159 + 81 = -159
Therefore:
-101 > -159
Answer: >
Write a pair of integers satisfying each condition.
(a) Sum = -7
-4 + (-3) = -7
Answer: -4 and -3
(b) Difference = -10
-25 - (-15) = -10
Answer: -25 and -15
(c) Sum = 0
4 + (-4) = 0
Answer: 4 and -4
(a) Two negative integers whose difference is 8
(-5) - (-13) = 8
Answer: -5 and -13
(b) A negative and positive integer whose sum is -5
-25 + 20 = -5
Answer: -25 and 20
(c) A negative and positive integer whose difference is -3
-2 - 1 = -3
Answer: -2 and 1
Team A:
-40 + 10 + 0 = -30
Team B:
10 + 0 + (-40) = -30
Both teams scored the same.
This also illustrates the commutative property of addition. Integers can be added in a different order without changing the sum.
Answer: Both teams scored -30. Yes, integers can be added in any order.
(i)
(-5) + (-8) = (-8) + (-5)
(ii)
-53 + 0 = -53
(iii)
17 + (-17) = 0
(iv)
[13 + (-12)] + (-7) = 13 + [(-12) + (-7)]
(v)
(-4) + [15 + (-3)] = [-4 + 15] + (-3)
These examples demonstrate the commutative, additive identity and associative properties of addition.
|
Expression |
Answer |
|
3 × (-1) |
-3 |
|
(-1) × 225 |
-225 |
|
(-21) × (-30) |
630 |
|
(-316) × (-1) |
316 |
|
(-15) × 0 × (-18) |
0 |
|
(-12) × (-11) × 10 |
1320 |
|
9 × (-3) × (-6) |
162 |
|
(-18) × (-5) × (-4) |
-360 |
|
(-1) × (-2) × (-3) × 4 |
-24 |
|
(-3) × (-6) × (-2) × (-1) |
36 |
(a)
18 × [7 + (-3)]
= 18 × 4
= 72
Right side:
(18 × 7) + [18 × (-3)]
= 126 - 54
= 72
Therefore:
LHS = RHS
(b)
(-21) × [(-4) + (-6)]
= (-21) × (-10)
= 210
Right side:
[(-21) × (-4)] + [(-21) × (-6)]
= 84 + 126
= 210
Therefore:
LHS = RHS
For any integer a:
(-1) × a = -a
Therefore:
Consider:
(-1) × 5 = -5
(-1) × 4 = -4
(-1) × 3 = -3
(-1) × 2 = -2
(-1) × 1 = -1
(-1) × 0 = 0
The product increases by 1 each time the second factor decreases by 1.
Therefore:
(-1) × (-1) = 1
This explains why the product of two negative integers is positive.
(a)
26 × (-48) + (-48) × (-36)
= -48[26 + (-36)]
= -48(-10)
= 480
(b)
8 × 53 × (-125)
= 8 × (-125) × 53
= -1000 × 53
= -53,000
(c)
15 × (-25) × (-4) × (-10)
= 15 × 100 × (-10)
= -15,000
(d)
(-41) × 102
= (-41) × (100 + 2)
= -4100 - 82
= -4182
(e)
625 × (-35) + (-625) × 65
= 625[(-35) + (-65)]
= 625 × (-100)
= -62,500
(f)
7 × (50 - 2)
= 350 - 14
= 336
(g)
(-17) × (-29)
= (-17) × (-30 + 1)
= 510 - 17
= 493
(h)
(-57) × (-19) + 57
= 57 × 19 + 57
= 57 × 20
= 1140
Initial temperature = 40°C
Decrease per hour = 5°C
Decrease in 10 hours:
5 × 10 = 50°C
Final temperature:
40 - 50 = -10°C
Answer: -10°C
Correct answer = +5 marks
Incorrect answer = -2 marks
(i) Mohan
4 correct:
4 × 5 = 20
6 incorrect:
6 × (-2) = -12
Total:
20 - 12 = 8 marks
(ii) Reshma
5 correct:
5 × 5 = 25
5 incorrect:
5 × (-2) = -10
Total:
25 - 10 = 15 marks
(iii) Heena
2 correct:
2 × 5 = 10
5 incorrect:
5 × (-2) = -10
Total:
10 - 10 = 0 marks
Profit on one white cement bag = ₹8
Loss on one grey cement bag = ₹5
(a)
3000 white bags:
3000 × 8 = ₹24,000 profit
5000 grey bags:
5000 × (-5) = -₹25,000
Net result:
24,000 - 25,000 = -₹1,000
Answer: Loss of ₹1,000
(b)
If 6400 grey bags are sold:
6400 × 5 = ₹32,000 loss
Let x be the number of white bags.
8x - 32,000 = 0
8x = 32,000
x = 4000
Answer: 4000 white cement bags
(a)
(-3) × (-9) = 27
(b)
5 × (-7) = -35
(c)
7 × (-8) = -56
(d)
(-11) × (-12) = 132
|
Expression |
Answer |
|
(-30) ÷ 10 |
-3 |
|
50 ÷ (-5) |
-10 |
|
(-36) ÷ (-9) |
4 |
|
(-49) ÷ 49 |
-1 |
|
13 ÷ [(-2) + 1] |
-13 |
|
0 ÷ (-12) |
0 |
|
(-31) ÷ [(-30) + (-1)] |
1 |
|
[(-36) ÷ 12] ÷ 3 |
-1 |
|
[(-6) + 5] ÷ [(-2) + 1] |
1 |
Remember:
For a = 12, b = -4 and c = 2:
LHS:
12 ÷ (-4 + 2)
= 12 ÷ (-2)
= -6
RHS:
(12 ÷ -4) + (12 ÷ 2)
= -3 + 6
= 3
Therefore:
-6 ≠ 3
So,
a ÷ (b + c) ≠ (a ÷ b) + (a ÷ c)
For a = -10, b = 1 and c = 1:
LHS = -10 ÷ 2 = -5
RHS = -10 + (-10) = -20
Again, LHS ≠ RHS.
|
Statement |
Missing integer |
|
369 ÷ ___ = 369 |
1 |
|
(-75) ÷ ___ = -1 |
75 |
|
(-206) ÷ ___ = 1 |
-206 |
|
-87 ÷ ___ = 87 |
-1 |
|
___ ÷ 1 = -87 |
-87 |
|
___ ÷ 48 = -1 |
-48 |
|
20 ÷ ___ = -2 |
-10 |
|
___ ÷ 4 = -3 |
-12 |
Examples:
Answer: Any five valid integer pairs can be used.
Initial temperature at noon = 10°C
Decrease each hour = 2°C
The temperature reaches -8°C after:
10 → 8 → 6 → 4 → 2 → 0 → -2 → -4 → -6 → -8
This takes 9 hours.
Answer: 9 p.m.
At midnight, 12 hours have passed:
10 + (12 × -2)
= 10 - 24
= -14°C
Answer: Midnight temperature = -14°C
Correct answer = +3 marks
Incorrect answer = -2 marks
(i) Radhika
12 correct answers:
12 × 3 = 36
Her total score is 20.
Marks from incorrect answers:
20 - 36 = -16
Number of incorrect answers:
-16 ÷ -2 = 8
Answer: 8 incorrect answers
(ii) Mohini
7 correct answers:
7 × 3 = 21
Total score = -5
Marks from incorrect answers:
-5 - 21 = -26
Number of incorrect answers:
-26 ÷ -2 = 13
Answer: 13 incorrect answers
Initial position = 10 m above ground
Final position = -350 m
Distance descended:
-350 - 10 = -360 m
Rate of descent = -6 m/min
Time:
360 ÷ 6 = 60 minutes
Answer: 60 minutes or 1 hour
When two integers have the same sign, add their absolute values and keep the common sign.
Example:
(-7) + (-5) = -12
When the signs are different, subtract the smaller absolute value from the larger one and keep the sign of the number with the larger absolute value.
Example:
-9 + 4 = -5
Subtracting an integer is the same as adding its opposite.
a - b = a + (-b)
Example:
8 - (-3) = 8 + 3 = 11
|
Signs |
Result |
|
+ × + |
+ |
|
+ × - |
- |
|
- × + |
- |
|
- × - |
+ |
Division follows the same sign pattern as multiplication.
|
Signs |
Result |
|
+ ÷ + |
+ |
|
+ ÷ - |
- |
|
- ÷ + |
- |
|
- ÷ - |
+ |
For every integer a:
a + 0 = a
and, when a ≠ 0:
0 ÷ a = 0
A number line helps you visualise positive and negative integers.
For example:
-5 < -2 < 0 < 3 < 7
A common mistake is to think that -5 is greater than -2 because 5 is greater than 2. On the number line, -5 lies to the left of -2, so -5 is smaller.
The sum, difference and product of two integers are integers.
For example:
7 + (-10) = -3
Addition and multiplication are commutative:
a + b = b + a
a × b = b × a
Subtraction and division are not generally commutative.
Addition and multiplication are associative:
(a + b) + c = a + (b + c)
(a × b) × c = a × (b × c)
Multiplication distributes over addition and subtraction:
a × (b + c) = a × b + a × c
a × (b - c) = a × b - a × c
Try these questions before checking the answers.
On a number line, -9 lies to the left of -4. Numbers become smaller as we move left.
Answer: -9 < -4
The additive inverse of a number is the number that gives zero when added to it.
-15 + 15 = 0
Answer: 15
The multiplicative identity is 1 because:
a × 1 = a
No.
For example:
8 - 3 = 5
but
3 - 8 = -5
Therefore:
8 - 3 ≠ 3 - 8
No.
For example:
12 ÷ 3 = 4
but
3 ÷ 12 = 1/4
Therefore, division is not commutative.
The sign changes.
Example:
(-18) × (-1) = 18
(-15) + (-8) + 20
= -23 + 20
= -3
-6 + 14 = 8°C
-600 + 250 = -350
The person still owes ₹350.
(-4) × [6 + (-2)]
= (-4) × 4
= -16
Before a test, remember these points:
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For the current 2026–27 NCERT Ganita Prakash textbook, students should check the new chapter numbering before using older Chapter 1 Integers material.

Integers are numbers that include negative whole numbers, zero and positive whole numbers. Examples are -5, -2, 0, 4 and 9.
The chapter covers the number line, addition and subtraction of integers, multiplication, division, properties of integer operations and word problems involving temperature, money, scores and position.
The product of two negative integers is positive.
For example:
(-6) × (-4) = 24
Yes. Addition of integers is commutative.
For example:
-5 + 8 = 3
and
8 + (-5) = 3
No. In the current 2026–27 Ganita Prakash textbook, Chapter 1 is Large Numbers Around Us. Integer operations are covered later in Chapter 10: Operations with Integers. This page retains the older Chapter 1 Integers intent because that is the chapter represented by this URL and its existing search demand.
