Averages Exercises: Measurements Money People
Averages
What is an average?
Averages are often used when we want to represent a series of numbers by one number. Adding up a series of numbers gives us a total number. Dividing this total by the number of numbers we added up gives us an average number.
What was the average number of people who successfully won money on the lottery between January and April, this year?
To work out the average, we need to do things:
i) Add up the number of people who won money for each month.
ii) Divide this total by the number of months we are covering.
Look at how many people won money on the lottery for each month between January and April
January – 72
February – 86
March – 109
April – 94
We now add up these numbers to find the total.
109
94
86 +
72
361
22
361 people won money on the lottery between January and April. To find the average, we need to divide 361 by the number of months that we have added together. In this case, we have used 4 months.
361 ÷ 4 = 90.25 (Rounded down to the nearest whole number = 90).
On average, 90 people won money on the lottery between January & April.
Averages are usually worked out by adding two or more numbers together and then dividing the total by the number of numbers used.
Here are the temperatures recorded in Limerick for each day last week. What was the average temperature?
Mon Tue Wed Thu Fri Sat Sun
14ºc 15ºc 17ºc 16ºc 14ºc 16ºc 17ºc
14
15
17 +
16
14
16
17
109
3
109 ÷ 7 = 15.5ºc
In cricket, batsmen work out their average for the season by adding together their scores and dividing the total by the number of times they have batted. So if, over the course of six innings, a batsman had scored a total of 142 runs, their average would be calculated by dividing 142 by 6.
142 ÷ 6 = 23.66*
* Note to potential cricket scorers: if the same batsman scored 142 runs in 6 innings but was not out in one of their innings, then the average would be worked out by dividing 142 by 5 instead. Cricket is the only instance when the rules concerning averages change.