Number Crunchers

[murali0298]

How do I improve speed on Number Crunchers leaving alone the large amount of practice?
Are there any short cuts on the HP Calculator because I just started using it but I don't know anything more about the calculator other than the basic rules of how to use it?

[nsguy1350]

Practice, even though you said without practice, that's really the only way, besides a couple of things I need to tell you. Here are a few tips, some on speed, some not.

You should be finishing with an HP32Sii in around 8:30 - 9:00. You shouldn't be missing many either; once you miss around 5, you're doing better, but at next year's competition season (D/R/S), I'd say aim to miss one or less (of course, less would be great, because at Region and State, a couple of NC misses can hurt you big time in calculator.)
There are a few things on the seventh page crunchers you should know.
#1. On #65, do NOT start at the beginning. Start somewhere in the middle, and work your way out. This is due to the HP RPN calculator having a four-slot-stack, which means it can only store four unique numbers at a time. #65 deals with problems that can overflow your stack working from left to right, so start in the middle instead.
#2. There are certain identities (you can figure them out) on the seventh page that you should see, that enable you to simplify expressions. If the expression is already sufficiently short, I don't bother using an identity, as you can see in a couple of trig problems.
#3. Speaking of trig, make sure you're in the right mode! To the left, it will tell you either (rad) or (deg).
#4. On some problems (specifically seventh page problems) you'll see a certain number or set of numbers repeated within a problem. Often, it looks like a Taylor series approximation to a function. I do not suggest using a Taylor series; some approximations converge quickly, and they work, but some do not and you must approximate using the given numbers (you can figure out which ones converge quickly and use the actual function for those, but I just crunch them all.) If a number repeats, use your calculator's store (STO) and recall (RCL) functions. In the top left of the keypad, when you enter a number (actually, you don't even need to press enter,) press STO and then a corresponding letter (most key has a letter closeby it, that serves as a variable storage, just like the TI calculators) to store it as that number. Maybe you'd like to store it as A or X; I suggest storing it as (H I believe?) the letter that is directly on the RCL button; that way, when you need to recall the number to use it again, you can just double tap RCL.
An example of keystroke sequence: 1 ENTER .37 STO RCL (storing it as the letter above RCL) + RCL RCL (recalling by double tap) x^2 2 / + RCL RCL 3 y^x 6 / + RCL RCL 4 y^x 24 / +.
By the way, that is a fourth-degree Taylor polynomial approximation for [unparseable or potentially dangerous latex formula] The approximation returns 1.45, while [unparseable or potentially dangerous latex formula] when rounded as well.
#5. There are a few more things, but I'd suggest reading the manual for now. Go #, search for the HP32Sii manual, and go read certain sections. That way, you get a deeper understanding of the calculator. Learn how to correct operation mistakes using LAST X, how to do linear regressions (for #47, a stated problem) and maybe even how to use the solver and integrate (I never learned, but it's always nice backing up your TI calculator, so you can switch to your HP when your TI is busy.) There are a few other things, but not much else that would really help you for the Calculator Applications contest. I guess I can tell you a few more things, but they are't really worth it at this point. Just get a good feel for your calculator and the problems that they give you, and you'll be fine.
#6. Oh, and lastly, a few suggestions on actually using the calculator: punch in numbers on your calculator with two hands, try not to rely on looking at the keyboard too much, hold your pen in one hand while you punch in your numbers, keep your calculator in your hand the entire time, so that you don't switch between calculator and pen the entire time, which wastes time (badly worded, basically I'm telling you to hold all in your hand at once so that you aren't wasting time by having to constantly pick things up/put things down,) and you can also check to make sure your answers make sense; "Number Sense" some problems very roughly to see if you're in range. Not all, just a few that you can see very easily.

[007math]

In my opinion, it's easier to leave the calculator on the desk.

[nsguy1350]

[007math]