Sum & Difference

Sum:

The sum of two or more numbers is the result obtained when they are added together.

For example: The sum of 18, 22, and 160 is 

18 + 22 + 160 =  200

 Difference:

The difference between two numbers is the result obtained when one of the numbers is subtracted from the other.

Positive difference: Larger Number – Smaller Number

Negative difference: Smaller Number – Larger Number

Worked Example 3.1.1:

Find the sum of the following:

a. 89 and 98
b. -75 and 105
c. -6.8 and -7.5
d. -7, -89 and 56

Solution

a. 89 and 98 = 187

b. -75 and 105

⇒ 105 – 75

= 30

c. -6.8 and -7.5

⇒ -6.8 – 7.5

= -14.3

d. -7, -89 and 56

⇒ 56 – 7 – 89 

= 56 – 96 = -40

Worked Example 3.1.2:

Add 15.5  to the positive difference between 43.6 and 27.8