Make choose function more obvious ie nCr

[FaisalAhmed123]

Problem you'd like to fix

nCr function is hard to find, and difficult to spot when looking back at history. This makes it difficult to navigate for A Level Maths Students (who learn it as the choose function rather than the terms permutation and combination)

Screenshots

Describe the solution you'd like

Add an option similar to the CG-50 which makes this more obvious, and easier to navigate. Image taken from Google of a CG-50's implementation

[adri1numworks]

We could think of changing the name of the function if needed. Can I ask you in which country this would be useful?

[MarcNumworks]

Note: when the country is set to Portugal they appear like this :

[FaisalAhmed123]

@adri1numworks Hi, I think it would be really useful as it is learnt as nCr in A-Level exams, the screenshot @MarcNumworks is perfect and would be great to have this in the UK too

[fbeleznay]

I attach a screenshot from the IB guide notation list.

IB uses the nCr and nPr notation. If you do change this, please do it well before an exam (the next one is in May) so that students can get used to it.

[adri1numworks]

OK this is well noted, thank you. We'll decide how we proceed and will let you know

[ukr-reader]

@FaisalAhmed123
Which exam board are you referring to? For Edexcel, the parenthesis notation is used in the formula book and textbooks. nCr is just given a small mention. Personally I would prefer the Numworks to keep the parentheses, or just offer nCr as an additional alternative.

[adri1numworks]

If any of you has the opportunity to provide us with more insight, it could be great. We will not make the change as long as we do not have a clear majority of persons requesting the nCk notation

[FaisalAhmed123]

@ukr-reader @adri1numworks

For pretty much all major exam board (EdExcel, OCR A, OCR MEI B) the nCr notation is used, I have attatched some screenshots below for reference across various revision resources

[FaisalAhmed123]

https://www.savemyexams.com/a-level/maths_pure/edexcel/18/revision-notes/4-sequences-and-series/4-1-binomial-expansion/4-1-1-binomial-expansion/

https://www.ocr.org.uk/blog/alevel-maths-binomial-expansion-pure-and-applied/

https://pmt.physicsandmathstutor.com/download/Maths/A-level/Pure/Sequences-and-Series-1/OCR-MEI-Set-A/Binomial%20Expansions%20(Yr.%201).pdf ((the mark scheme uses nCr notation))

Most students are familiar with nCr notation, however very few are familiar with the parentheses notation. However I agree it would be great to add both for clarity

[adri1numworks]

How would you see it? Adding the two right next to each other or create two different buttons? In the last option, I'm afraid it would confuse students rather than help them.

[r-mills]

Hi,

This doesn't need to be changed. Please don't change this!

For Pearson Edexcel, the largest exam board for A Level maths in the UK, the 'bracket' notation is the primary notation used, so students must be familiar with this and therefore this should be the notation used on the Numworks, as it currently is.

The formula booklet gives the binomial expansion primarily using this notation:

In mark schemes, the bracket notation is given in the working for the solution:

The official textbook introduces binomial expansion using the bracket notation:

And finally, and perhaps most critically, a previous examination question has used the bracket notation without any reference to nCr:

Thank you.

[jrkimber]

Hi,

To add to what r-mills says above, binomial coefficients are also used in the binomial distribution in A-Level maths.

Seen here in the formula book, using only the bracket notation:

And here in the official textbook:

And again in a textbook example, demonstrating how students would lay out their workings:

On a different note, if you were to make an improvement to the choose function, it would be nice for it to be in the toolbox, along with |x|, nth root and log_a, since it's such a frequently used function.

But yes, please don't change the notation, it would be a real backwards step.

Thanks,
James

[fbeleznay]

As far as I see, all comments above are for the UK exam boards. I would like to repeat that the current official IB notation is the nCr notation, so I would still think that in IB exam mode the nCr notation would be useful. I am not sure what the "international" option of the country selection covers, but if it is only the IB, then maybe if the country is set to "international", then the notation can be changed.

[adri1numworks]

Thank you all for your inputs. It is now excluded that we change the notation in UK. We are considering it for the IB exam and the International mode but we still have to make sure it would not enter in conflict with any exam boards.