A class ran a book drive for 4 days. The numbers of books collected on the 4 days were 11, 5, 0 and 8. Find the average number of books collected in a day.
Average = 24 ÷ 4 = 6 books
Ans: 6 books
Example 1
Find the average of 9, 0, 14, 6 and 11.
Average = 40 ÷ 5 = 8
Ans: 8
How to solve it
Think of each number as a bar. Even the bars out so they are all the same height. That height is the average.
Levelling adds nothing and throws nothing away, so find the total: 11 plus 5 plus 0 plus 8 is 24 books.
Count the pieces of data. There are 4 days, and the day with 0 books still counts.
Divide the total by the number of pieces: 24 divided by 4 is 6 books.
The average does not have to be one of the given numbers.
Levelling doesn't change the total. We only share it out equally, and the height the bars settle at is the average. Every number in the set is one bar, and a 0 is one of them.
Practice questions with worked solutions
Question 1 is free to try. The other 9 open in the free trial, each with its full working.
Question 1 of 10 · Basic · free to tryThe table shows the points Jovan scored in the five rounds of a school quiz…The table shows the points Jovan…
The table shows the points Jovan scored in the five rounds of a school quiz league. He was away on the day of round 2, so he was given 0 points for that round. What was his average score per round?
What should you remember when finding the average in P6?
This first Average page teaches the definition your child will use in every later question: average is the total value divided by the number of data.
What your child learns here
This first Average page teaches the definition your child will use in every later question: average is the total value divided by the number of data. Levelling bars to the same height shows what the average means, so the formula is not just a rule.
Understand average as 'total value ÷ number of data'.
Count every piece of data, including a value of 0.
Choose the right count when a question mentions two different groups, such as boxes and the items inside them.
Give an average as a decimal or with units when the division does not come out whole.
Does the answer make sense?
An average must lie between the smallest and largest values in the data, so levelled bars never stand taller than the tallest one. When your child's data includes a 0, such as the quiz round Jovan missed, the average must come out lower than the average of the other values alone.
How to practise these questions
Basic questions train dividing a total by the number of values, including sets that contain a zero value, and averages that come out as decimals. Intermediate questions add what an average cannot tell you about any one member of the group. Challenge questions treat the average as a target to reach, or measure the total in a less obvious unit. If the idea of levelling the bars is not clear, read the written step-by-step solution.
Questions parents ask
Is average in the Primary 6 syllabus? Yes. The MOE Primary 6 syllabus covers 'average as total value ÷ number of data' and the relationship between average, total value and number of data, under Statistics.
Does a zero count when finding the average? Yes. A zero adds nothing to the total, but it is still one of the data, so it counts in the number you divide by.
Does the average have to be one of the numbers in the set? No. The average of 3, 4 and 8 is 5, which is not in the set. It can also be a decimal, such as 2.5.
