Help with a mathematical Equation please

Aug 02, 2005 20 Replies

Apologies if this is the wrong group - all the maths groups I could find were over-run with spam posts.



I'm drawing up a spreadsheet and need to workout an equation, but my head is somewhat at sea at the moment, and am therefore struggling to get my head around it.



Lets say figure A is 1000 Figure B is 100



Somehow, I need an equation that will show Figure C is 10% - i.e the percentage figure B is to figure A.



It seems like this should be really simple - perhaps I need more coffee!



Thanks to anyone that can help


=B/A format the cell(s) holdoing the equations as percentage

In message of Tue, 2 Aug 2005, GRUK writes

If cell A1 is 1000 and cell B1 is 100 try cell C1 as ±/A1 and format cell C1 as percentage to as many decimal places as you fancy.

DF

Thanks Blackthorn, David Floyd and Andy Hawkins - all sorted and working now, I knew it was a simple one!

It always seems easier when it's in black and white!

Thanks again

In message , GRUK writes

If I'm reading what you want properly then you want C=(b/a)*100

In message of Tue, 2 Aug 2005, snipped-for-privacy@privacy.net writes

The OP needed the cell to show 10% eg. Therefore the cell needs to be formatted as a percentage, in which case the *100 isn't required.

David

In message of Tue, 2 Aug 2005, Andy Hawkins writes

The OP asked for the cell to show eg 10% therefore the cell needs to be formatted as a percentage, in which case the *100 isn't required.

David

or you put a % symbol in the cell to the right, which can have its advantages.

Phil

"Such as? "

knowing what's going to happen if you cut & paste the value or use it in a formula elsewhere. I have seen many screw ups with people typing "10" into a spreadsheet cell formatted as % with it resulting in a value of 1000% or equally referencing a value displayed as 10% and expecting its value to be 10 and not 0.1

keeping the % symbol and the number value separate is more predictable in its outcome, especially if you use different packages.

Phil

C=(B/A)*100 is clearer and prevents the computer/calculator misinterpreting it as C=B/(A*100)

Robert

"Robert" wrote

What computer or calculator would misinterpret "B/A*100" as "B/(A*100)" ?

wrote

But you should also know that 10% is the same as 0.10.

wrote

Equally, you get screw ups using your method when people try multiplying something by the % and expect (say) 10% of 150.00 to come out as 15.00, but actually get 1500.00!!

Both screw ups are possible so it depends upon the individual and the application. In which case Phil is quite correct to say that putting the % symbol in the cell to the right can have its advantages. Not that I'd ever do it.

true, but I have seen several occasions where people go on to use the answer 10% (=0.1) in a format a*b/100 and I have sat watching people typing 12 into a cell containing 10% to try a different interest rate.

it is in my experience less likely to happen if the number is clearly a number in a cell with a unit (%) expressed in the adjacent cell.

Some equations full of 100 and 10000 divisors are published in textbooks, people copy them into spreadsheets then reference a %formatted value and the wheels fall off.

Neither method is idiot proof, but I can see why there may be situations or individuals that are happier typing an integer number in rather than a decimal fraction which changes on entry due to cell formatting.

Phil

"Phil Thompson" wrote

Have you actually tried the above > >Equally, you get screw ups using your method when people

"Phil Thompson" wrote

I've found quite the opposite! [Perhaps it's a result of the circles of people we move around in?! :-( ]

In message , Tim writes

Polish reversed perhaps? As by the Jedi used.

A friend of mine at school always used to take one of these calculators as a spare to exams to lend to anyone who had left theirs behind!

A weak response I know, but: The calculator could be a person. Robert

it does indeed do that in the current version of Excel. Does it do it in all previous versions or in other spreadsheet packages ? I know at least one that does not (Lotus 123)

this approach can lead people to prefix things with £ $ or ? and expect the spreadsheet to do currency conversions. Excel doesn't do this and is therefore inconsistent in its handling of such things.

Might be good for media studies graduates but it drives engineers mad. Horses for courses, there is a role for the separate unit rather than the in-cell formatting approach.

Phil

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