Class 6 Maths Chapter 1 Important Question Answers - Integers

Q1: The temperature on a certain morning is -11℃ at 5 a. m. If the temperature drops 3 degree at 6 a.m. and rises 5 degree at 8 a.m. and again drops 3 degree at 9 a.m. What is the temperature at 9 a.m.?
Ans: Temperature at 5 a.m. = -11℃
Temperature decreased at 6 a.m. = 3℃ = -3
Temperature raised at 8 a.m. = 5℃ = +5
Temperature decreased at 9 a.m. = 3℃ = -3
Final temperature at 9 a.m. = (-11) + (-3) + (+5) + (-3)
= -11 – 3 + 5 – 3
= -17 + 5
= -12℃.

Q2: Find the value of: (–7) + (–9) + 4 + 16.
Ans: (–7) + (–9) + 4 + 16
= (–16) + 20
= (–16) + 16 + 4
= 0 + 4 = 4

Q3: Find the solution of the following: (–9) + (+13)
Ans: (–9) + (+13)
= (–9) + (+9) + (+4)
= 0 + (+4) = +4

Q4: Write four negative integers less than –20.
Ans: Four negative integers less than –20 are -21, -22, -23 and – 24.

Q5: Fill in the blanks:
(a) When we subtract -10 from 18 we get ______.
(b) _____ is an integer which is neither positive nor negative.
(c) 272 – 198 – ______ = 0.
(d) 15 + _____ = 0.
Ans: (a) 28;
(b) 0;
(c) 74;
(d) -15

Q6: Sum of (– 9) and 15.
Ans: -9 + 15 = 15 – 9 = 6

Q7: Fill in the blanks with >, < or = sign. (– 3) + (– 6) ______ (– 3) – (– 6)
Ans: -3 -6 = -9
-3 – (-6) =- 3 +6 = 6- 3 = 3
so -9 < 3

Q8: Write numbers with appropriate signs: 40^∘C below 0^∘C temperature.
Ans: below means less than 0 so it is – 40.

Q9: Using number line, add the following integers: 9 + (-6).
Ans: On the number line we first move 9 steps to the right from 0 reaching 9 and then we move 6 steps to the left of 9 and reach 3.
Thus, 9 + (-6) = 3


Q10: Subtract: (–20) – (–13)
Ans: (–20) – (–13)
= (–20) + (additive inverse of -13)
= (–20) + (13) = –7

Q11: Write all the integers between -8 and -15. (Write them in the increasing order.)
Ans: The integers between –8 and –15 in increasing order are –14, –13, –12, –11, –10 and –9.

Q12: State whether the following statements are true or false:
(a) If a and b are any two integers such that a > b, then -a > – b.
(b) If the sum of an integer and its opposite is zero, then they are called additive inverses of each other.
(c) The negative of 0 is -0.
(d) The sum of positive and negative integers is always negative.
Ans: (a) False
(b) True
(c) False; zero is neither negative nor positive
(d) False

Q13: Match the following:
Ans:

Q14: The number of integers between -2 and 2 is
Ans: integers between -2 and 2 are -1, 0, 1 so 3 integers

Q15: 2 subtracted from 7 gives
Ans: 7 – 2 = 5