# AQA COMP3 June 2012 Exam Thread Tweet

Computer Science and ICT discussion, revision, exam and homework help.

Announcements Posted on
IMPORTANT: You must wait until midnight (morning exams)/4.30AM (afternoon exams) to discuss Edexcel exams and until 1pm/6pm the following day for STEP and IB exams. Please read before posting, including for rules for practical and oral exams. 28-04-2013
1. Re: AQA COMP3 June 2012 Exam Thread
(Original post by foolscap)
yeah it said "the most negative number" is was like, wtf that's stupid.
That's what I thought. I wonder if it's a mistake? I just put the smallest negative number: 1.000000 1000
2. Re: AQA COMP3 June 2012 Exam Thread
(Original post by mfmdanny)
I think the -12.5 is wrong. Didn't it ask for normalised floating point? So the first 2 bits must be 1.0 or 0.1

Also, did it say "the largest negative number"?
I thought it said "the most negative number," I was like... Huh?
for the -12.5 i got:

mantissa as: 1.001110
exponent as: 00100
3. Re: AQA COMP3 June 2012 Exam Thread
(Original post by mfmdanny)
I think the -12.5 is wrong. Didn't it ask for normalised floating point? So the first 2 bits must be 1.0 or 0.1

Also, did it say "the largest negative number"?
I thought it said "the most negative number," I was like... Huh?
Oh yeah, -12.5 is:

mantissa 1.001110 and exponent is 00100
4. Re: AQA COMP3 June 2012 Exam Thread
(Original post by ms607)
yeah they mean the same thing?

in which case I got that wrong as I think I put the smallest -ve number
That's what I put!

What's the same thing?
5. Re: AQA COMP3 June 2012 Exam Thread
(Original post by mfmdanny)
That's what I thought. I wonder if it's a mistake? I just put the smallest negative number: 1.000000 1000
Pretty sure I saw similar phrase used in the old spec that meant biggest negative number, i put 1.000000 0111, you got the mantissa right so 1/2 marks i think you'll get.
6. Re: AQA COMP3 June 2012 Exam Thread
(Original post by mfmdanny)
That's what I put!

What's the same thing?
most negative number = largest negative number?
7. Re: AQA COMP3 June 2012 Exam Thread
The number closest to negative infinity is 1.0000001 0111 because when you convert it to denary you convert the mantissa first to a positive number ie - 01111111
8. Re: AQA COMP3 June 2012 Exam Thread
(Original post by ms607)
most negative number = largest negative number?
Yes.
9. Re: AQA COMP3 June 2012 Exam Thread
(Original post by SecondHand)
The number closest to negative infinity is 1.0000001 0111 because when you convert it to denary you convert the mantissa first to a positive number ie - 01111111
largest negative normalised number is 1.000000 with an exponent of 01111
10. Re: AQA COMP3 June 2012 Exam Thread
(Original post by foolscap)
Yes.
Surely the largest negative number is as close to 0 as possible.

This is probably why they used most negative instead.
11. Re: AQA COMP3 June 2012 Exam Thread
(Original post by steve ex)
Surely the largest negative number is as close to 0 as possible.

This is probably why they used most negative instead.
the smallest negative number is the one closest to zero. the largest is the number closest to -infinity
12. Re: AQA COMP3 June 2012 Exam Thread
(Original post by Edwin Okli)
On another note. I kind of made a revision guide (from the textbook and other notes). I'll attach it here and people can tell me if there are any mistakes or content that needs to be added.

(Too large to be attached.)
Again, thank you so much for making that revision guide! Was extremely useful (especially when the school library was locked at like 11:30 and I luckily had that revision guide on my phone)
13. Re: AQA COMP3 June 2012 Exam Thread
(Original post by Ninjaelephant)
the smallest negative number is the one closest to zero. the largest is the number closest to -infinity
I suppose it depends on your definition of largest. Is largest the biggest number, or the number furthest from 0?
14. Re: AQA COMP3 June 2012 Exam Thread
for the most negative number i took it as basically the negative largest number... The way i was taught this was to first work out the largest number in its positive form.
so that would be: 0.1111111 01111
then perform 2s a complement on the mantissa so it ends up being: 1.0000001 01111 ??
15. Re: AQA COMP3 June 2012 Exam Thread
(Original post by _VJ)
for the most negative number i took it as basically the negative largest number... The way i was taught this was to first work out the largest number in its positive form.
so that would be: 0.1111111 01111
then perform 2s a complement on the mantissa so it ends up being: 1.0000001 01111 ??
I thought it was 1.000000 0111
16. Re: AQA COMP3 June 2012 Exam Thread
Any rough guesses for boundaries?
17. Re: AQA COMP3 June 2012 Exam Thread
did the add device procedure need to have a (override)?
i put it in but i think I was wrong
and for the second one about laptops i put another override

the first one was three marks so makes sense for it not to be there
18. Re: AQA COMP3 June 2012 Exam Thread
Any guesses for boundaries and a mark scheme would be nice!
19. Re: AQA COMP3 June 2012 Exam Thread
(Original post by exam2k10)
Any rough guesses for boundaries?
Personally I think the grade boundaries would be slightly lower than usual, as new questions have popped up which haven't appeared (mainly due to there being only 2 previous papers and there are so many topics to cover). So looking at the past 2 grade boundaries and judging from the reasonably straight forward, yet easily to slip up on paper today I'd say:

A* = 79 / 100

A = 69 / 100

B = 60 / 100

C = 51 / 100

That's just me estimating though and I could be horribly wrong
20. Re: AQA COMP3 June 2012 Exam Thread
(Original post by rugito)
did the add device procedure need to have a (override)?
i put it in but i think I was wrong
and for the second one about laptops i put another override

the first one was three marks so makes sense for it not to be there
Yeh, you'd need override for adding a new device. I didn't put NewDevice in the laptop class definition. I don't know if it needed it, but I didn't see any relevance, I just had function GetBluetoothInstalled or whatever it was