CLASS-7
RULES OF ADDITION OF INTEGERS

ADDITION OF INTEGERS 

Addition Rules of Integers –

a) To add two positive integers, add their absolute values, and attach the positive sign.

b)To add two negative integers, add their absolute values and attach the negative sign and to add two integers of opposite signs, find the difference of their absolute values and attach the sign of the integer with the greater absolute value.

If a, b, c are the integers then-  a + b = b + a

                  (a+b) + c = a + (b+c) = a + b + c

The sum of any integer and zero ‘0’ is the integer itself. In other words, if a is an integer then.

          a + 0 = a, zero here is nothing but additive identity.

Addition of two or more integers of same sign – 

To add the two or more integers with the same sign (negative & positive), first we have to add and find their absolute value and then attach the common sign with the obtained value.

Example.1)  Add (+120)  & (+65)

So, (+120) + (+65)  =  120 + 65 = 185   (Ans.)

 

Example.2) Add (-35) & (-75)

So, (-35) + (-75) = -110    (Ans.)

 

Addition of two or more integers with opposite sign –

a) First we have the find the absolute value of given integers

b) subtract the smaller absolute value from the bigger absolute value.

c) to the difference in step 2, attach the sign of the integers which has the larger absolute value

 

Example.1) Add (-45) & (+10)

(-45) + (+10) = -45 + 10 = -35     (Ans.)