AP State Syllabus AP Board 6th Class Maths Solutions Chapter 4 Integers Ex 4.3 Textbook Questions and Answers.

## AP State Syllabus 6th Class Maths Solutions 4th Lesson Integers Ex 4.3

Question 1.

Add the following integers using number line.

i) 7 + (-6)

ii) (-8) + (-2)

iii) (-6) + (-5) + (+2)

Answer:

i) 7 + (-6)

On the number line, we first move 7 steps to the right of 0 to reach +7.

Then, we move 6 steps to the left of +7 and reach + 1.

So, 7 + (-6) = 1

ii) (-8) + (-2)

On the number line, we first move 8 steps to the left of 0 to reach -8.

Then, we move 2 steps to the left of -8 and reach -10.

So,(-8) + (-2) = -10

iii) (-6) + (-5) + (+2)

On the number line, we first move 6 steps to the left of 0 to reach -6.

We move 5 steps to the left of -6 and reach -11.

Then, we move 2 steps to the right of -11 and reach -9.

So, (-6) + (-5) + (+2) = -9

Question 2.

Add without using number line.

(i) 10 + (-3)

(ii) 10 + (+16)

(iii) (-8) + (+8)

Answer:

i) 10 + (-3)

10 + (-3) = 7 + 3 + (-3) = 7 + (3 + (-3))

= 7 + 3 – 3 = 7 + 0

∴ 10 + (-3) = +7

ii) -10 + (+16)

-10 + (+16)

= -10 + 10 + 6

= (-10 + 10) + 6

= 0 + 6

∴ -10 + (+16) = + 6

iii) (-8) + (+ 8)

-8 + (+8) = -8 + 8 = 0

∴ -8 + (+8) = 0

Question 3.

Find the sum of i) 120 and -274 ii) -68 and 28

Answer:

i) 120 and-274

Method -1: Sum = + 120 + (-274)

= + 120 + (- 120 – 154)

= + 120 – 120 – 154

∴ 120 + (-274) = -154

Method – II:

As the given numbers have opposite sign, we subtract one from other

As 274 is having negative (-) sign, the answer is – 154.

ii) -68 and 28

Sum = – 68 + (28)

= – 40 – 28 + 28

∴ – 68 + 28 = – 40

Question 4.

Simplify:

i) (-6) + (-10) + 5 + 17

ii) 30 + (-30) + (-60) + (-18)

Answer:

i) (-6) + (-10) + 5 + 17

– 6 – 10 + 5 + 17 = -16 + 22

= -16 + 16 + 6

= + 6

∴ (-6) + (-10) + 5 + 17 = + 6

ii) 30 + (-30) + (-60) + (-18)

= 30 + (-30 -60 -18)

= 30 + (-108)

= 30 – 108 = – 78

∴ 30 + (-30) + (-60) + (-18) = -78