Primary 6 · Average · Question type 5.3
When a value is added to a set, calculate the old and new totals before finding the new average.
Try the question yourself, or watch the lesson first.
Primary 6, on the MOE Primary Mathematics syllabus.
The lesson · 2 minutes 20 seconds
Watch: a 5 kg parcel put on a trolley of 4 parcels
Another worked example
A veterinary clinic looks after 2 cats with an average age of 4 years and three times as many dogs with an average age of 5 years. What is the average age of all 8 animals?
The working · Four lines
Written out in full, the way it should appear on paper.
The answer is 4.75 years.
Practise · Modelled on top school exam questions
Try it yourself first, then enter your answer to check it. Open the solution when you want to see the steps. No sign-up is needed. These questions are written by Mathweave, not copied from school papers.
Try it yourself
Keep track of the total and the number of players.
The average height of 5 players in a basketball squad is 146 cm. The tallest player, who is 158 cm tall, leaves the squad. What is the average height of the 4 players who are left?
Ans: 143 cm
The practice plan adds more questions and saved progress.
Next, find how many data values were in the original set. Average with the Number of Values Unknown →