My dc has come across a question in the Bond Practice Test Maths 11+, which is included in the Bond How to do... Maths book.

Q 50. A door is 5 feet 9 inches high. Which is the closest to its height in meters? Circle the correct answer.
the options are 1.5m 1.6m 1.7m 1.8m 1.9m

Bearing in mind that our dc are taking their respectice tests at the end of Year 5, are they really expected to know the conversion of Imperial to Metric units data?

Tagore

It's in KS2 (cf http://goo.gl/JK5GI)

But that's a shocking question, because the answer hinges on the precision of the conversion factor you use. The correct value is 2.54cm = 1" (because a yard is now defined to be 0.9144m), so 69 x 2.54 = 1.7526m, making the answer 1.8m. But if you use the typical KS2 conversion factor of 2.5cm ~ 1", you get 69 x 2.5 = 1.725m, making the answer 1.7m. 2.5cm ~ 1" is off by nearly 0.5cm per foot, hence the near-3cm difference. It's a pretty fundamental law of setting multiple-choice questions which permit an approximation that the candidate gets credit for providing the correct answer as well.

Thank you daveg. I agree it is a shocking question but will have to get dc to remeber all the conversion data.
Tagore

Common imperial units and their metric equivalents are in KS2 maths curriculum.

I would have worked it out like this:
Most upper KS2 should know a 30cm ruler is similar to 12" or 1' so:
5 x 30cm = 150cm
9" is 3/4 of a foot; 3/4 of 30cm = 22.5cm
150 + 22.5 = 172.5cm = 1.7m rounded

Right. But if they happen to know the correct conversion, they'll get 1.8m. And that's why it's a badly constructed question: the correct answer and the answer that is expected aren't the same.

Most of the questions I have seen of this type for this age of kids are looking for a reasonable answer

eg a man is 6ft tall is he 1.8cm 180cm 1.8m or 18m tall

Where does your child do 11plus for this year OP?

Mystery - I assume the questions asked of me, since I initiated this thread (but I could not make the connection with OP). My dc is going to take her 11+ for NW London and SW Herts schools.
Tagore