# 2013 Numeracy results. Is 5.00 not a whole number??

Discussion in 'Primary' started by emillers, Jun 28, 2013.

1. ### mystery10Occasional commenter

Ah thanks. Don't all these questions and mark schemes get tested beforehand? I wonder what the teacher feedback was.

Mine would be:

-it's tough to get 2 answers absolutely correct and get no marks for this - this actually bothers me more than the other issue

-the mark scheme should give some credit (but not full credit) for rounding in the correct direction but giving an answer with some superfluous "trailing zeros" ( I like that term).

I'm pedantic and those trailing zeros drive me to distraction. When I see them on my children's work I have to sellotape my lip to stop me saying "why don't they teach you maths properly?!"

Unfair of me I know. As I said above, it's a tough thing when something as relatively trivial as this at this stage in maths can make a significant difference in a child's NC level and what is predicted for GCSE etc on Raiseonline etc.

"Rounding" (of decimals) involves two processes, truncating and adjustment.

What you are calling "rounding" is only the adjustment part of the process

A candidate might well feel agrieved if he/she was not aware of the truncating requirement.

3. ### mystery10Occasional commenter

Yes. The adjustment is arguably harder than the truncation so no marks is mean, as is zero marks for 2 out of 4. If the whole paper was structured like this a child could get zero marks despite getting half of it right.

Except that the truncation is the whole purpose of the exercise.

The adjustment is merely to lessen the inaccuracy caused by the truncation. If you don't truncate, you don't need to adjust.

5. ### mystery10Occasional commenter

I am not sure about that.

Round 5.05 to one significant figure - the answer is 5

Round 505 to one significant figure - the answer is 500.

These are both rounding but the second one involves no truncation by your definition.

I was careful to say "Rounding" (of decimals) involves two processes, truncating and adjustment.'

The NC, KS2 maths limits itself to "rounding to an integer", I believe.

However, to round 505 to one SF, the truncation reduces it to 5 and the adjustment includes padding with two zeros to get 500.

Or you could write it as 5.05 * 10^2, truncate to 5 * 10^2 and then apply the adjust algorithm, which would of course, leave it unchanged in this case.

7. ### mystery10Occasional commenter

Yes, if you put the words "of decimals" in as you have done so, the statement is correct. However, I still wouldn't necessarily agree that the whole purpose of the exercise was truncation. Only the question setter and mark scheme writer could tell us this surely. The particular way the mark scheme is built up seems unnecessarily harsh in this question - and particularly so the way that you could get 2 out of 4 answers absolutely correct (both the adjustment and truncation aspects) and get zero marks.

It's even correct without that, but the adjustment would involve adding extra zero(s) before the decimal point.

But anyway,

I guess the chief examiner has his reasons. If you don't know how to round on a question which tells you to round, you don't get any marks seems to be his philosophy. He probably thinks he is being too kind in allowing something for answers with even just one error.

Chief examiner (imagined comment): "Rounding is specifically mentioned in the syllabus. The question has been set before. It's time those pesky teachers knew what was required....If I let this go the nation's children will never know how to round a number!"

9. ### mystery10Occasional commenter

Oh I did not mean that though. Nomad said there were four items to round in the question. You get 1 mark if three answers are absolutely correct, and two marks if four answers are correct.

So you could be able to round and get zero marks.

If you are able to round, why do you get any of the four wrong?

11. ### mystery10Occasional commenter

It's a very good question, albeit a scary one. Children, and adults also, make mistakes - even with things they know and can do - and particularly in test situations.

Do you not find this to be the case?

Yes, of course - to err is human. The examiner gives something for 3 correct answers, acknowledging the possibility that a simple error rather than ignorance may have occurred. But two incorrect suggests ignorance rather than repeated slips.

Re mistakes - my experience has taught me that the winner is the person who makes the fewer mistakes - in all walks of life.

13. ### mystery10Occasional commenter

Is there any technical reason why one slip is a simple slip, but two slips suggests ignorance?

14. ### SansAtoutNew commenter

Yes, there are technical reasons

Firstly, there were two numbers where you needed to round up (5.55, 4.54) and two numbers where you rounded down (4.45, 5.05). If a pupil wrongly believed that you simply truncated, they would get two right, Similarly, if they always rounded up, they would get two correct. Getting three right is more symptomatic of a slip.

Secondly, if you guessed randomly whether to round up or down, you have a 25% chance of getting 3 out of 4 right, but a 62.5% chance of getting either 2 or 3 right, and you want to minimise the awarding of marks to a good guesser.