Primary 6 · Average · Question type 5.2
Multiply the average by the number of data values, then subtract the known values to find the missing one. The count includes the missing value, not just the values shown.
Try the question yourself, or watch the lesson first.
Primary 6, on the MOE Primary Mathematics syllabus.
The lesson · 2 minutes 6 seconds
Watch: 5 weeks of newspaper, with Week 3 left as a question mark
Another worked example
Three planters in a nursery hold an average of 42 seedlings each. The first planter holds 30 seedlings. The third planter holds twice as many seedlings as the second. How many seedlings are in the third planter?
The working · Five lines
Written out in full, the way it should appear on paper.
The answer is 64 seedlings.
Practise · Modelled on top school exam questions
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Try it yourself
Use the total for all the readings to find the missing one.
The average amount of rain over four months, from April to July, was 46.5 mm. The rain recorded was 52 mm in April, 39 mm in May and 44 mm in June. How much rain was recorded in July?
Ans: 51 mm
The practice plan adds more questions and saved progress.
Next, compare the totals before and after a value is added. Finding the New Average When a Value Joins →