Class β 6 CH-6 INTEGERS
MATHS NCERT SOLUTIONS
Exercise 6.1
Question 1 :
Write opposite of the following:
(a) Increase in weight
(b) 30 km north
(c) 326 BC
(d) Loss of βΉ700
(e) 100 m above sea level
Solution 1:
(a) Decrease in weight
(b) 30 km south
(c) 326 AD
(d) Profit of βΉ700
(e) 100 m below sea level
Question 2:
Represent the following numbers as integers with appropriate signs.
(a) An aeroplane is flying at a height two thousand meters above the ground.
(b) A submarine is moving at a depth eight thousand meters below the sea level.
(c) A deposit of rupees two hundred.
(d) Withdrawal of rupees seven hundred.
Solution 2:
(a) (+) 200 meters
(b) (β) 800 meters
(c) (+) 200 Rupees
(d) (β) 700 Rupees
Question 3:
Represent the following numbers on number line:
(a) +5
(b) β10
(c) +8
(d) β1
(e) β6
Solution 3:
Question 4:
Adjacent figure is a vertical number line, representing integers. Observe it and locate the following
points:
points:
(a) If point D is +8 then which point is β8?
(b) Is point G a negative integer or a positive integer?
(c) Write integers for points B and E.
(d) Which point marked on this number line has the least value?
(e) Arrange all the points in decreasing order of values.
Solution 4:
(a) F
(b) Negative
(c) B = (+) 4; E = (β) 10
(d) E
(e) D, C, B, A, O, H, G, F, E
Question 5:
Following is the list of temperatures of five places in India, on a particular day of the year.
Place Temperature
Siachin 10Β°C below 0Β°C ____________________
Shimla 2Β°C below 0Β°C ____________________
Ahmedabad 30Β°C above 0Β°C ____________________
Delhi 20Β°C above 0Β°C ____________________
Srinagar 5Β°C below 0Β°C ____________________
(a) Write the temperature of these places in the form of integers in the blank column.
(b) Following is the number line representing the temperature in degree Celsius.
Plot the name of the city against its temperature.
(c) Which is the coolest place?
(d) Write the names of the place where temperature are above 10Β°C.
Solution 5:
Place Temperature
(a) Siachin (β) 10Β°C
Shimla (β) 2Β°C
Ahmedabad (+) 30Β°C
Delhi (+) 20Β°C
Srinagar (β) 5Β°C
(c) Siachin is the coolest place.
(d) Ahemadabad and Delhi
Question 6:
In each of the following pairs, which number is to the right of the other on the number line?
(a) 2, 9
(b) β3, β8
(c) 0, β1
(d) β11, 10
(e) β6, 6
(f) 1, β100
Solution 6:
(a) 9 is right to 2
(b) β3 is right to β8
(c) 0 is right to β1
(d) 10 is right to β11
(e) 6 is right to β6
(f) 1 is right to β100
Question 7:
Write all the integers between the given pairs (write them in the increasing order):
(a) 0 and β7
(b) β4 and 4
(c) β8 and β15
(d) β30 and β23
Solution 7:
(a) β6, β5, β4, β3, β2, β1
(b) β3, β2, β1, 0, 1, 2, 3
(c) β14, β13, β12, β11, β10, β9
(d) β29, β28, β27, β26, β25, β24
Question 8:
(a) Write four negative integers greater than β20.
(b) Write four negative integers less than β10.
Solution 8:
(a) β19, β18, β17, β16
(b) β11, β12, β13, β14
Question 9:
For the following statements write True (T) or False (F). If the statement is false, correct the statement:
(a) β8 is to the right of β10 on a number line.
(b) β100 is the right of β50 on a number line.
(c) Smallest negative integer is β1.
(d) β26 is larger than β25.
Solution 9:
(a) True
(b) False
(c) False
(d) False
Question 10:
Draw a number line and Solution the following:
(a) Draw a number line will we reach if we move 4 numbers to the right of β2.
(b) Which number will we reach if we move 5 numbers to the left of 1.
(c) If we are at β8 on the number line, in which direction should we move to reach β13?
(d) If we are at β6 on the number line, in which direction should we move to reach β1?
Solution 10:
(c) On left side
(d) On right side
β
Exercise 6.2
Question 1:
Using the number line write the integer which is:
(a) 3 more than 5
(b) 5 more than β5
(c) 6 less than 2
(d) 3 less than β2
Solution 1:
(a) 8
(b) 0
(c) β4
(d) β5
Question 2:
Use number line and add the following integers:
(a) 9 + (β6)
(b) 5 + (β11)
(c) (β1) + (β7)
(d) (β5) + 10
(e) (β1) + (β2) + (β3)
(f) (β2) + 8 + (β4)
Solution 2:
(a) 9 + (β6) = 3
(b) 5 + (β11) = β6
(c) (β1) + (β7) = β8
(d) (β5) + 10 = 5
(e) (β1) + (β2) + (β3) = β6
(f) (β2) + 8 + (β4) = 2
Question 3:
Add without using number line:
(a) 11 + (β7)
(b) (β13) + (+18)
(c) (β10) + (+19)
(d) (β250) + (+150)
(e) (β380) + (β270)
(f) (β217) + (β100)
Solution 3:
(a) 11 + (β7) = 11 β 7 = 4
(b) (β13) + 18 = 5
(c) (β10) + (+19) = β10 + 19 = 9
(d) (β250) + (+150) = β250 + 150 = β100
(e) (β380) + (β270) = β380 β 270 = β650
(f) (β217) + (β100) = β217 - 100 = β317
Question 4:
Find the sum of:
(a) 137 and β354
(b) β52 and 52
(c) β213, 39 and 192
(d) β50, β200 and 300
Solution 4:
(a) 137 + (β354) = 137 β 354 = β217
(b) (β52) + 52 = 0
(c) (β312) + 39 + 192 = β312 + 231 = β81
(d) (β50) + (β200) + 300 = β50 β 200 + 300 = β250 + 300 = 50
Question 5:
Find the value of:
(a) (β7) + (β9) + 4 + 16 (b) 37 + (β2) + (β65) + (β8)
Solution 5:
(a) (β7) + (β9) + 4 + 16
= β7 β 9 + 4 + 16
= β16 + 20
= 4
(b) 37 + (β2) + (β65) + (β8)
= 37 β 2 β 65 β 8
= 37 β 75
= β38
Exercise 6.3
Question 1:
Subtract:
(a) 35 β (20)
(b) 72 β (90)
(c) (β15) β (β18)
(d) (β20) β (13)
(e) 23 β (β12)
(f) (β32) β (β40)
Solution 1:
(a) 35 β 20 = 15
(b) 72 β 90 = β18
(c) (β15) β (β18) = β15 + 18 = 3
(d) β20 β (13) = β20 β 13 = β33
(e) 23 β (β12) = 23 + 12 = 35
(f) (β32) β (β40) = β32 + 40 = 8
Question 2:
Fill in the blanks with >, < or = sign:
(a) (β3) + (β6) _______________ (β3) β (β6)
(b) (β21) β (β10) _______________ (β31) + (β11)
(c) 45 β (β11) _______________ 57 + (β4) (d) (β25) β (β42) _______________ (β42) β (β25)
Solution 2:
(a) (β3) + (β6) <(β3) β (β6)
(b) (β21) β (β10) > (β31) + (β11)
(c) 45 β (β11) > 57 + (β4)
(d) (β25) β (β42) > (β42) β (β25)
Question 3:
Fill in the blanks:
(a) (β8) + __________ = 0
(b) 13 + __________ = 0
(c) 12 + (β12) = __________
(d) (β4) + __________ = β12
(e) __________ β 15 = β10
Solution 3:
(a) (β8) + 8 = 0
(b) 13 + (β13) = 0
(c) 12 + (β12) = 0
(d) (β4) + (β8) = β12
(e) 5 β 15 = β10
Question 4:
Find:
(a) (β7) β 8 β (β25)
(b) (β13) + 32 β 8 β 1
(c) (β7) + (β8) + (β90)
(d) 50 β (β40) β (β2)
Solution 4:
(a) (β7) β 8 β (β25)
= β7 β 8 + 25
= β15 + 25
= 10
(b) (β13) + 32 β 8 β 1
= β13 + 32 β 8 β 1
= 32 β 22
= 10
(c) (β7) + (β8) + (β90)
= β7 β 8 β 90
= β105
(d) 50 β (β40) β (β2)
= 50 + 40 + 2
= 92