Maths. Saw this on our video? Tap the answer your child chose to check it, then open the worked answer to see why the tempting wrong options catch so many children out.
Question 17Aim for about 60 seconds
Four consecutive whole numbers add up to 70. What is the smallest of them?
Show the worked answer
Answer: D, 16
How to work it out
The middle of the run is the mean: 70 ÷ 4 = 17.5 (halfway between the two middle numbers).
The numbers are 16, 17, 18, 19.
The smallest is 16.
Why the other options are wrong
A (17): This is one too many; check by adding the run: 16, 17, 18, 19.
B (19): This is the largest number, not the smallest.
C (18): This is the mean, 70/4, which is the middle of the run, not the smallest.
E (8): This is half the correct answer, 16. Check whether you halved when you should not have.
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