Chapter - 6 - EXERCISE 6.3 - Integers (NCERT Class 6th Maths Solution)

Q1. Find
(a) 35 – (20)                                                              (b) 72 – (90)
(c) (– 15) – (– 18)                                                      (d) (–20) – (13) (e) 23 – (– 12)
(f) (–32) – (– 40)

Solution/Explanation:

To subtract two integers, we add the additive inverse of the integer that is being subtracted.
So 2 -5 = 2+ (-5) as -5 is additive inverse of 5
Now we have already learned the addition of integers before

a)	35 − (20) = 35+ (-20)	Subtract 35 and 20 and put the sign of the bigger number 35, which is positive 15
b)	72 − (90) 72+(-90)	Subtract 72 and 90 and put the sign of the bigger number 90, which is negative -18
c)	(− 15) − (− 18) = (-15) + (18) As additive inverse of -18 is 18	Subtract 15 and 18 and put the sign of the bigger number 18, which is negative 3
d)	(− 20) − (13) = (-20) + (13)	Subtract 20 and 13 and put the sign of the bigger number 20, which is negative -7
e)	23 − (− 12) =23+12	Adding the numbers 23 and 12= 35
f)	(− 32) − (− 40) = (-32) + (40)	Subtract 32 and 40 and put the sign of the bigger number 40, which is negative 8

Q2. Fill in the blanks with >, < or = sign. 

(a) (– 3) + (– 6) ______ (– 3) – (– 6) 

(b) (– 21) – (– 10) _____ (– 31) + (– 11) 

(c) 45 – (– 11) ______ 57 + (– 4) 

(d) (– 25) – (– 42) _____ (– 42) – (– 25)

Solution/Explanation:

Q3. Fill in the blanks. 

(a) (– 8) + _____ = 0 

(b) 13 + _____ = 0 

(c) 12 + (– 12) = ____ 

(d) (– 4) + ____ = – 12 

(e) ____ – 15 = – 10

Solution/Explanation:

a)	(− 8) + _____ = 0	8
b)	13 + _____ = 0	-13
c)	12 + (− 12) = ___	0
d)	(− 4) + _____ = − 12	-8
e)	_____ − 15 = − 10	5

Q4.  Find 

(a) (– 7) – 8 – (– 25) 

(b) (– 13) + 32 – 8 – 1 

(c) (– 7) + (– 8) + (– 90) 

(d) 50 – (– 40) – (– 2) 

Solution/Explanation:

(a)$(-7)-8-(-25)=(-15)-(-25)=(-15)+25=10$
(b)$(-13)+32-8-1=19-8-1=11-1=10$
(c) $(-7)+(-8)+(-90)=(-15)+(-90)=(-105)$
(d) $50-(-40)-(-2)=50+40-(-2)=90-(-2)=90+2=92$