The arithmetic mean of numbers is the sum of these numbers divided by the number of terms.
| arithmetic mean = sum of all numbers / number of terms |
To find the arithmetic mean of numbers, add these numbers and divide the result by the number of numbers. ( In the case of finding the arithmetic mean of two numbers, divide by 2, in the case of three 3, etc.)
Examples of finding the arithmetic mean of two numbers
Example 1: Find the arithmetic mean of two numbers: 
Example 2: Find the arithmetic mean of the three numbers 
If necessary, can an ordinary fraction 
convert to decimal
Example 3: Find the average of four numbers: 
The problem of finding the arithmetic mean
Task 1: while travelling in the car for the first hour passed 
, away, for the second 
km and for third and fourth — 
what is the average per hour drove the car?
In this task, on the average it is necessary to find average of numbers 
— average miles per hour drove the car.
Task 2: Candy red poppy stand 
UAH per kg, and the starry night - 
UAH per kg. Marina bought 
kg of a red poppy, a pound starry night. And Alenka bought 
kg of a red poppy and 
kg starry night. What is the average purchase price of Marinka and Alenka?
Marina spent 
Helen spent 
In this task, on the average it is necessary to find average of numbers 
— an average of UAH spent Marinka and Alenka.