7 Maths GCSE Questions

Xordium · 22 Aug 2013 at 23:14

7/7 - questions do seem easier than they used to be but kids work harder - of that I am sure. I seem to remember doing nothing then walking into exams. These days you do seem to have to jump through a ridiculous amount of hoops. And the stuff they get little ones doing now is pretty scary.

King4aDay · 22 Aug 2013 at 23:27

6

But I am just finishing off my second bottle of wine

estebanrey · 22 Aug 2013 at 23:31

muon said:
Excel would spit out an error if you did that. There is no implied multiplication in 4 3/5.

I was talking about order of operations in reference to Excel not the lack of operators which is a different issue.

Excel does not calculate if you omit the '*' operator, this is something exclusive writing equations down. But it will follow the order of operation where parentheses are missing. So it calculates...

=4+3*4

and

=4+(3*4)

both as 16.

muon · 22 Aug 2013 at 23:45

estebanrey said:
I was talking about order of operations in reference to Excel not the lack of operators which is a different issue.

Excel does not calculate if you omit the '*' operator, this is something exclusive writing equations down. But it will follow the order of operation where parentheses are missing. So it calculates...

=4+3*4

and

=4+(3*4)

both as 16.

Well * explicitly tells excel it is a product. So that is cheating.

How does order of operations explain that 4 3/5 = 12/5?

Note how wolfram alpha interprets it

http://www.wolframalpha.com/input/?i=4+3/5&dataset=

chriscubed · 22 Aug 2013 at 23:56

7. Used the calculator for the VAT question but otherwise easy. Clearly the test isn't representative of the GCSE so I'm not sure what the point of it is.

estebanrey · 23 Aug 2013 at 00:06

muon said:
Well * explicitly tells excel it is a product. So that is cheating.

How does order of operations explain that 4 3/5 = 12/5?

Note how wolfram alpha interprets it

http://www.wolframalpha.com/input/?i=4+3/5&dataset=

You are straying way off the comment I was responding to. The claim was that the "correct" way of writing 4 3/5 would be 4(3/5). I was trying to point out that technically the brackets are redundant (and hence his claim was false) as they both come to the same result.

muon · 23 Aug 2013 at 00:22

estebanrey said:
You are straying way off the comment I was responding to. The claim was that the "correct" way of writing 4 3/5 would be 4(3/5). I was trying to point out that technically the brackets are redundant (and hence his claim was false) as they both come to the same result.

I think you've misinterpreted his comment.

4(3/5) implies multiplication to most people. 4*3/5 as you've stated.

4 3/5 doesn't to anyone as far as I know.

People would read the latter out as Four and Three Fifths.

[TW]Sponge · 23 Aug 2013 at 00:29

3. Hate maths.

estebanrey · 23 Aug 2013 at 00:40

muon said:
I think you've misinterpreted his comment.

4(3/5) implies multiplication to most people. 4*3/5 as you've stated.

4 3/5 doesn't to anyone as far as I know.

People would read the latter out as Four and Three Fifths.

In the algebraic notation, widely used in mathematics, a multiplication symbol is usually omitted wherever it would not cause a confusion: "a multiplied by b" can be written as ab or a b.

Wiki

SlyReaper · 23 Aug 2013 at 08:35

Mason- said:
I would never use a mixed fraction.

This. I don't think I've ever even heard of a mixed fraction before this nonsense. I say again, this is from a guy with a maths degree. It's completely artificial. If you absolutely must represent rationals that way, then put a plus sign between the integer and the fraction. With nothing in between, the default operator is multiplication, not addition. Maths is all about eliminating ambiguity like that.

AJK · 23 Aug 2013 at 08:35

estebanrey said:
In the algebraic notation, widely used in mathematics, a multiplication symbol is usually omitted wherever it would not cause a confusion: "a multiplied by b" can be written as ab or a b.

Wiki

Yeah, this obviously doesn't work with digits though, does it? You can't write "43" and expect people to come up with 12.

SlyReaper said:
This. I don't think I've ever even heard of a mixed fraction before this nonsense. I say again, this is from a guy with a maths degree. It's completely artificial. If you absolutely must represent rationals that way, then put a plus sign between the integer and the fraction. With nothing in between, the default operator is multiplication, not addition. Maths is all about eliminating ambiguity like that.

I think you're all missing the point that GCSE Maths does explicitly cover mixed numbers, and the presentation of a question containing the number "4 3/5" which explicitly asks for a mixed number as the answer would not confuse a GCSE Maths student...

It's all very well commenting "well, as someone with a maths degree this is rubbish" but these questions aren't from a degree, are they?

dirtychinchilla · 23 Aug 2013 at 08:39

estebanrey said:
You are straying way off the comment I was responding to. The claim was that the "correct" way of writing 4 3/5 would be 4(3/5). I was trying to point out that technically the brackets are redundant (and hence his claim was false) as they both come to the same result.

muon said:
I think you've misinterpreted his comment.

4(3/5) implies multiplication to most people. 4*3/5 as you've stated.

4 3/5 doesn't to anyone as far as I know.

People would read the latter out as Four and Three Fifths.

This is immensely tedious.

Adsta · 23 Aug 2013 at 08:44

6 out of 7. I got a mixed number sum wrong (doh)

SlyReaper · 23 Aug 2013 at 09:08

AJK said:
Yeah, this obviously doesn't work with digits though, does it? You can't write "43" and expect people to come up with 12.

I think you're all missing the point that GCSE Maths does explicitly cover mixed numbers, and the presentation of a question containing the number "4 3/5" which explicitly asks for a mixed number as the answer would not confuse a GCSE Maths student...

It's all very well commenting "well, as someone with a maths degree this is rubbish" but these questions aren't from a degree, are they?

That's a pretty damning indictment of GCSE maths.

estebanrey · 23 Aug 2013 at 09:10

AJK said:
Yeah, this obviously doesn't work with digits though, does it? You can't write "43" and expect people to come up with 12.

Jeez, again people need to follow the discussion. The original equation was...

At least 3 or 4 other people as well as me said they saw that as 4 times 3 over 5 minus 3 times 1 over 3.

3 over 5 is a symbol, not a single digit. It is only because computer keyboards don't allow you to type fractional symbols that it's ended up looking like "4 3/5".

At the end of the day, I don't know anyone that would write it like the picture above anyway. They'd put "4.6 - 2.333..."

dirtychinchilla · 23 Aug 2013 at 09:27

To avoid having to write 4.6 or 2.3333333333333333333333333333333333333333333333

AJK · 23 Aug 2013 at 09:32

estebanrey said:
Jeez, again people need to follow the discussion.

I've read it, thank you.

At least 3 or 4 other people as well as me said they saw that as 4 times 3 over 5 minus 3 times 1 over 3.

Because you are applying a post-GCSE mentality to the question. GCSE Maths (and previous KS levels of course) teaches mixed numbers, so when presented with a question involving mixed numbers, requiring an answer using mixed numbers, the GCSE student will treat the question as mixed numbers. End of.

As far as I recall, implied multiplication is only taught at GCSE in the context of lettered notation in algebra. So again, a GCSE student would not assume that multiplication is taking place here.

Are you saying I'm wrong in some way because I read the question, read what kind of answer was required, and drew a sensible conclusion?

At the end of the day, I don't know anyone that would write it like the picture above anyway. They'd put "4.6 - 2.333..."

Yes, in a question about mixed numbers, and teaching students to deal with fractions, that would make perfect sense.

No, wait... it wouldn't.

Helios1234 · 23 Aug 2013 at 09:33

That was at best Year 6 level Maths apart from the trig question.

Anyway, 7/7.

AJK · 23 Aug 2013 at 09:34

SlyReaper said:
That's a pretty damning indictment of GCSE maths.

What is? That the material taught at GCSE isn't of the same level as the material taught at degree level? Honestly, I don't get it...

Xordium · 23 Aug 2013 at 09:37

SlyReaper said:
That's a pretty damning indictment of GCSE maths.

No it's not. It's indicative of an approach which does not assume that children are merely small adults and takes them through a path of learning that is appropriate for their age and for the broad range of abilities seen.