ADDING AND SUBTRACTING POSITIVE AND NEGATIVE NUMBERS

Simplify the following :

Problem 1 :

(-12) + (-1)

Solution :

(-12) + (-1)

Since these are having same signs, we add them and put greater number's sign for the answer.

= -12 – 1

= -13

Problem 2 :

(-9) + 11

Solution :

Since the given two numbers are having different signs, subtract the smaller from larger and use the sign of the larger number to the answer.

(-9) + 11 = 2

Problem 3 :

(-4) + (-8) + 11

Solution :

(-4) + (-8) + 11

Simplify the numbers which are same signs first.

= -4 – 8 + 11

= -12 + 11

Now we have different signs, so we subtract them and put greater number's sign for the answer.

= -1

Problem 4 :

3 + (-11) + 8

Solution :

= 3 + (-11) + 8

Combine the numbers which are having same signs first.

= 3 + 8 - 11

= 11 - 11

= 0

Problem 5 :

(-4) + 6 + (-3)

Solution :

(-4) + 6 + (-3)

= -4 + 6 – 3

= 2 – 3

= -1

Problem 6 :

1 + (-4) + 10

Solution :

1 + (-4) + 10

First combine the terms which are having same signs.

= 1 + 10 - 4

=  11 - 4

Since they are having different signs, subtract 4 from 11 and put positive sign for the answer.

= 7

Problem 7 :

(-5) + (-5) + 1

Solution :

(-5) + (-5) + 1

First combine the terms which are having same signs.

= -5 - 5 + 1

= -10 + 1

Since they are having different signs, subtract 1 from 10 and put negative sign for the answer.

= -9

Problem 8 :

1 + (-3) + 11

Solution :

1 + (-3) + 11

First combine the terms which are having same signs.

= 1 + 11 - 3

= 12 - 3

Since they are having different signs, subtract 3 from 12 and put positive sign for the answer.

= 9

Problem 9 :

(-9) + 4 + 7

Solution :

First combine the terms which are having same signs.

= (-9) + 4 + 7

= -9 + 11

Since they are having different signs, subtract 3 from 12 and put positive sign for the answer.

= 2

Problem 10 :

(-12) + 4 + 8

Solution :

(-12) + 4 + 8

= -12 + 12

= 0

Problem 11 :

3 + (-10) + 6

Solution :

= 3 + (-10) + 6

= 9 - 10

= -1

Problem 12 :

(-3) + 3 + 12

Solution :

= (-3) + 3 + 12

= -3 + 15

= 12

Problem 13 :

(-4) – (-8) - 2

Solution :

(-4) – (-8) - 2

= -4 + 8 – 2

= -4 - 2 + 8

= -6 + 8

= 2

Problem 14 :

(-2) – (-1) - (-7)

Solution :

= (-2) – (-1) - (-7)

= -2 + 1 + 7

= -2 + 8

= 6

Problem 15 :

2 – (-5) - 3

Solution :

= 2 – (-5) - 3

= 2 + 5 – 3

= 7 – 3

= 4

Problem 16 :

(-7) – (-7) - 4

Solution :

= (-7) – (-7) – 4

= -7 + 7 – 4

= -7 - 4 + 7

= -11 + 7

= -4

Problem 17 :

(-6) – 4 – (-4)

Solution :

= (-6) – 4 – (-4)

= -6 – 4 + 4

= -10 + 4

= -6

Problem 18 :

(-8) – (-8) - 5

Solution :

= (-8) – (-8) - 5

= -8 + 8 – 5

= -8 - 5 + 8

= -13 + 8

= -5

Problem 19 :

(-5) – 6 - (-6)

Solution :

= (-5) – 6 - (-6)

= -5 – 6 + 6

= -11 + 6

= -5

Problem 20 :

6 – (-3) - 1

Solution :

= 6 – (-3) - 1

= 6 + 3 – 1

= 9 – 1

= 8