Integer numbers are the whole number which cannot represent in fractions or decimals.
Fundamental operations of integers: -
Addition of integers:
a) When integers have like sign i.e., when both the integers to be added are either positive or negative, add their absolute values and assign the same sign to the sum.
Example: - Add the following:
i) +57 and +112
ii) -32 and -83
Solution: -i) Here, both he integers to be added are positive and their absolute values are 57 and 112 respectively.The sum of their absolute values = 57 + 112 = 169
Therefore (+ 57) + (+ 112) = + 169
ii) Here, both the numbers to be added are negative and their absolute values are 32 and 83 respectively.
The sum of their absolute values = 32 + 83 = 115
Therefore (- 32) + (- 83) = - 115
Thus, on adding two or more positive integers, we always get a positive number. Similarly, on adding two or more negative integers, we always get a negative number.
b) When the integers have unlike sign i.e., one is positive and the other is negative: -
Determine the difference of their absolute values and to this difference assign the sign of integer of greater absolute value.
Example: - Add + 53 and – 29
Solution: -The absolute values of +53 and -29 are 53 and 29 respectively;
And their difference = 53 – 29 = 24
Since, the integer with the greater absolute value is 53 and its sign is ‘ + ‘.
Therefore (+ 53) + (- 29) = + 24