## Integers

EXERCISE 1.2

CBSE Class 7 Maths

**Q1: 1. Write down a pair of integers whose:**

**(a) sum is –7**

**(b) difference is –10**

**(c) sum is 0**

Answer:

(a) One such pair whose sum is -7 = -4 + (-3) = -7

(b) One such pair whose difference is -10 = -3 - 7 = 10

(c) One such pair whose sum is 0 = -5 + 5 = 0

**Q2:**

**(a) Write a pair of negative integers whose difference gives 8.**

**(b) Write a negative integer and a positive integer whose sum is –5.**

**(c) Write a negative integer and a positive integer whose difference is –3.**

Answer:

(a) -2 + (-10) - (3 + 1) = 8

(b) -7 + 2 = -5

(c) -1 - (2) = -3

**Q3: In a quiz, team A scored – 40, 10, 0 and team B scored 10, 0, – 40 in three successive rounds. Which team scored more? Can we say that we can add integers in any order?**

Answer:

Team A scored -40, 10, 0

Total score of Team A = -40 + 10 + 0 = -30

Team B scored 10, 0, -40

Total score of Team B = 10 + 0 + (-40) = 10 _ 0 - 40 = -30

Thus, scores of both teams are same.

Yes, we can add integers in any order due to commutative property.

**Q4: Fill in the blanks to make the following statements true:**

**(i) (–5) + (............) = (– 8) + (............)**

**(ii) –53 + ............ = –53**

**(iii) 17 + ............ = 0**

**(iv) [13 + (– 12)] + (............) = ............ + [(–12) + (–7)]**

**(v) (– 4) + [............ + (–3)] = [............ + 15] + ............**

Answer:

(i) (–5) + (–8) = (–8) + (–5) [Commutative Property]

(ii) –53 + 0 = –53 [Zero Additive Property]

(iii) 17 + (–17) = 0 [Additive Identity]

(iv) [13 + (–12)] + (-7) = 13 + [(–12) + (–7)] [Associative Property]

(v) (– 4) + [15 + (–3)] = [ -4 + 15] + (-3) [Associative Property]

__MCQs (Q5 - Q 7)__

**Q5: Sum of two negative number is always**

(a) Positive

(b) Negative

(c) 0

(d) 1

Answer: (b) Negative

**Q6: The pair of integers whose sum is -5**

(a) 1, -4

(b) -1, 6

(c) -3, -2

(d) 5, 0

Answer: (c) -3, -2

**Q7: What will be the additive inverse of -5**

(a) -6

(b) -4

(c) 3

(d) 5

Answer: (d) 5

**Q8: Write the following in ascending order:**

**1, 0, 2, -3, 4, -7**

Answer: -7, -3, 0, 1, 2, 4

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