Addition is the basic arithmetic operation often used while the others are multiplication, subtraction and division. The term addition counts the given numbers as together what we call adding. It is in fact the sum of given numbers. 

If x and y are the given numbers. The addition formula is given by sum z given as,
z = x + y.

If $a_1$, $a_2$, $a_3$,........an are given numbers. The addition formula is given by,

Z = $a_1$ + $a_2$ + $a_3$ +........ + $a_n$.

Where z is the sum of the given numbers.

Let's see some addition Examples:

Question 1: Jimmy is a party organizer of his class. He tells all the 5 person in the class to bring some fruits. If Joe brings 5 bananas, amie brought 4 apples, brown brought 6 pear, jeff brings 2 oranges and allen brings 5 litchi. How many fruits are there in total?
Solution:

Given: $a_1$ = 5, $a_2$ = 4, $a_3$ = 6, $a_4$ = 2, $a_5$ = 5

The  addition formula is given by,
Z = $a_1$ + $a_2$ + $a_3$ + $a_4$ + $a_5$
Z = 5 + 4 + 6 + 2 + 5
Z = 22 fruits

Question 2: Mary scores 22 in English, 18 in Maths, 23 in Science, in Social science she is getting 12 in history and 13 in geography. What is the total marks she is getting out of 100?
Solution:

Given: a1 = 22, a2 = 18, a3 = 23, a4 = 12, a5 = 13

The  addition formula is given by,
Z = $a_1$ + $a_2$ + $a_3$ + $a_4$ + $a_5$
Z = 22 + 18 + 23 + 12 + 13
Z = 88 marks.