A Great RPN Calculator


We were having company for supper last night. 

To make it special for the little ones, we decided to serve Kentucky Friend Chicken.  Now, there hasn’t been a store in Amherstburg in years so guess who got to drive into Windsor to get it?

As I stared at the menus, I remembered the good old days when they served chicken and cole slaw.  Things really have changed.  The menus are huge.  So, I’m standing there doing a little, actually a lot, of mental math to try to determine what the best value would be.  I selected and ordered.  There would be a fifteen minute wait while they cooked the chicken!  I looked at the clock – it wasn’t anywhere near one o’clock, the traditional end of the lunch hour!  How could they be out?  <grin>

Well, we wanted to do it so I decided to order and wait.  To kill some time, I pulled out my phone and started doing some math with the pricing on the menus.  It wasn’t a horrific task; there were math questions all over the place.  What’s the best value?  Is the price of a bowl of cole slaw the same with every order?  What’s the best value for pop that’s available in three sizes? As my kids would point out, these are the reasons I sit alone in public places.

There were so many things to calculate, I soon find that I’m doing the math on the standard calculator that comes on my Android and realize that it wasn’t efficient use of my time.  Then, I clued in.  I was using an algebraic calculator.  I could be much more efficient with an RPN Calculator.  You may recall that I’ve blogged about this before and before.  I thank my university statistics professor for recommending my original HP21 calculator. 

Chicken isn’t cooked so I’m off to the Google Play store to look for an RPN Calculator to download.

It turns out there were a LOT of them.  One in particular caught my eye because it was the spitting image of the HP products that I was so fond of.

 

 

I became really engrossed with this program.  It’s such a nice and faithful copy of the original – even to the LED display that couldn’t be read in bright sunlight!

Other than just using the calculator, the whole experience brought back a few problems from my computer science classroom.  First, you have to teach students just what RPN is and then have them write the code.  The HP 21 had a nice rolling stack of 4 which led right into another sort of topic that you’ll only find in a computer science classroom.  And, the nice thing about writing your own calculator program is that you can add feature after feature, including printing graphs.  Function keys extend the function of any of the buttons.  It’s just a shame that we had to use a mouse to press the buttons at the time.

Sir, your chicken is ready.

Well, the moment has passed but I’ve been inspired to get the application and play with it.  Who says mathematics can’t be fun?

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OTR Links 09/24/2014


Posted from Diigo. The rest of my favorite links are here.