VAT calculations with RPN-calculator « Next Oldest | Next Newest »

 ▼ Kalevipoeg Junior Member Posts: 28 Threads: 10 Joined: Jun 2007 11-26-2005, 04:51 AM I like to tell you how I became more familiar with % function of the HP12c. VAT = Value Added Tax (in the European Union) ```NET = GROSS/(1+(VAT RATE/100)) VAT = NET*(VAT RATE/100) ``` I wanted to write a short program which a) calculates NET amount into Y register and b) calculates VAT into X register. In this case VAT RATE is stored in R0-register. Usage: Key in the GROSS amount and press [R/S]. First I wrote the following program (16 steps) ```01 RCL 0 02 1 03 0 04 0 05 / 06 1 07 + 08 / 09 ENTER 10 ENTER 11 RCL 0 12 1 13 0 14 0 15 / 16 * ``` Then I realized my calculator has a % function and I wrote my program again (now 7 steps) ```01 1 02 RCL 0 03 % 04 + 05 / 06 RCL 0 07 % ``` The % function of the RPN-calculators is more useful function than I believed! ▼ Karl Schneider Posting Freak Posts: 1,792 Threads: 62 Joined: Jan 2005 11-27-2005, 01:55 AM Kalevipoeg -- Good thinking! Of course, "per cent" means "per 100", so those are logical simplifications. Among Voyagers, only the HP-12C and HP-10C have a "%" key as an unshifted function. I believe that "%" is much more useful in business than in science and engineering, in which "delta-%" is more useful. It makes sense to me that the 12C would have "%" unshifted. However, the basic scientific 10C omitted "delta-%", while providing "%" unshifted. Not good thinking... tony (nz) Member Posts: 93 Threads: 2 Joined: Jul 2005 11-28-2005, 01:05 AM Hello Kalevipoeg. Nice to see you again. Today I learned from Wikipedia that you must be the son of Kalev :-) Indeed it can be very handy the way % preserves Y. I once had fun using i,PV and FV (with n=1 and PMT=0) to do all shopkeeper markup/markdown calculations, which parallel VAT/normal_tax(eg income tax) calculations. The markdown and income tax percentages need to be entered as negative. It takes a bit of getting used to as PV and FV have opposite signs, but we usually know which is the larger. And then PV+FV gives the amount of the tax for example. Yes, I remember now, last year in Datafile V23N2P14/15, I wrote about this - also showing how to calculate markup given markdown, and vice-versa. So you could set FV=GROSS, i=VAT RATE. Then solving for PV gives -NET. You can input any two, and solve for the third - not that this is very useful, except if you are a tax consultant or a shopkeeper :-) But it is fun to try and do many calculations, actually seen in daily life, with one equation: PV*(1+i/100)+FV=0. BTW I have submitted some 12C games to HPCC Datafile and I mention your name in bold when presenting lunar lander, referring folk to your Moon Landing Simulator as published here early last month. I hope you don't mind - I never thought to ask! Cheers, Tony ▼ Kalevipoeg Junior Member Posts: 28 Threads: 10 Joined: Jun 2007 11-28-2005, 01:45 AM Thank you Tony. I'm happy you mentioned my name. Thanks. About VAT calculations Why did I want to calculate NET amount into Y register and VAT into X register? Answer: Now I can use Sigma+ to calculate totals if necessary. Edited: 28 Nov 2005, 7:41 a.m.

 Possibly Related Threads... Thread Author Replies Views Last Post [PRIME] RPN: another attempt at returning more than one value to the RPN stack Marcus von Cube, Germany 5 760 11-05-2013, 02:44 AM Last Post: Marcus von Cube, Germany Another non-HP RPN vintage calculator joins the collection Michael de Estrada 2 563 07-23-2013, 04:10 PM Last Post: Walter B OT: RPN calculator/dmm by ESI Kees van der Sanden 2 500 05-25-2013, 01:38 PM Last Post: Kees van der Sanden "HP RPN Calculator Users" group on LinkedIn Philippe Lasnier 6 703 04-27-2013, 03:27 AM Last Post: BruceH [wp34s] Alternative MIO (allows calculations when entering element values) David Maier 1 319 02-03-2013, 02:51 PM Last Post: Marcus von Cube, Germany Financial Calculations for the HP41: another enhanced version Luiz C. Vieira (Brazil) 0 213 04-16-2012, 09:16 AM Last Post: Luiz C. Vieira (Brazil) [WP 34S] Complex calculations (poll) Walter B 41 2,552 04-08-2012, 01:44 AM Last Post: Paul Dale OT: RPN calculator for Garmin GPS hpnut 3 414 03-22-2012, 08:44 AM Last Post: Andrés C. Rodríguez (Argentina) The smallest ever LED RPN calculator Michael de Estrada 11 853 02-16-2012, 10:24 PM Last Post: Bill Wiese Wang 360 RPN calculator aj04062 8 740 11-07-2011, 08:20 PM Last Post: aj04062

Forum Jump: