A terrific little calculator,
possibly the best in its class
(allowed on NCEES exams).
Wikipedia : Calculators | TI-36X Pro (2011)
Generalities :
How to use a Scientific Calculator
by LearnersCloud.
Specific instructional videos for the TI-36X Pro :
Solving a quartic equation, by Eddie.
Standard deviation with TI-36X Pro, by Elmexico7.
Replacing the Battery
(CR2032 battery) by EngineeringUndergrad.
solar power &
lithium battery
(CR2032)
Dimensions :
(with cover)
width: 83.3 mm
length: 171.5 mm
(183.3 mm)
height: 15 mm
(18 mm)
weight: 116 g
(148 g)
41 keys + D-pad
dot-matrix LCD
96 by 31 pixels
4 lines of 16 characters
(5 by 7 font)
or 2D layout
13-digit precision
(10 digits shown)
8 variables: x,y,z,t,a,b,c,d
list price: 25ドル
street price: 19ドル
manufactured by Kinpo.
The key labeled "clear" (top-right corner, below the prominent 4-way navigation button) is used to recover from errors and/or clear the screen.
Yet, the "clear" key by itself doesn't invalidate changes made in the setup screen (which is accessed via the "mode" key, at the top left of the keypad) or any other menu that allows multiple changes.
To clear the calculator's memory and return it a pristine condition with all its factory settings (including angles in degrees) you may push the "on" and "clear" key simultaneously. This has the same effect as the full "reset" obtained by punching in "2nd", "0" and then "2" (for "yes").
The "delete" key at the middle of the top row is far less drastic, as it deletes one element at a time (usually the last one entered but you may also target something else with the navigation button).
On basic calculators, every key has a single use. This wouldn't be practical for calculators that offer many functions. Advanced calculators often feature several modifiers keys (shift-keys) that allow access to multiple functionalities for regular keys. The TI-36X Pro only has one such shift-key (colored blue and labeled "2nd" at the top-left corner of the keyboard).
Yet, this calculator offers a lot of functionality by taking advantage of the multi-tap approach which is so popular for alphabetic entry on telephone keypads: To obtain the different meanings of a key, just press it several times...
The calculator doesn't have to impose any time limit between the taps because it's designed so that there is never a need to use different meanings of the same key twice in a row. (Well, this means that you must enter i*p instead of ip, even if you find the latter more elegant.)
The double-tap method is clearly superior to a separate shift key for single-finger operation of a keypad (every key acts as a shift-key for itself, so to speak, without a journey across the keypad). Other calculator designers have been wasting at least one shift-key by forsaking multi-tap.
The designers of the TI-36X Pro may have overused this by cramming all of its 8 variables (x,y,z,t,a,b,c,d) on a single key, which you must press 8 times to access "d".
[画像: Come back later, we're still working on this one... ]
Videos :
How to Reset the
Texas Instruments TI-36X Pro Calculator by Modyw94 (2012年09月28日)
and TI-36X PRO Programming Bug by
Nick Weil (2012年01月16日).
If you didn't attend elementary school in the US or the UK, you may be puzzled by the so-called mixed fraction representation of positive rationals: The integral part is followed by the "fractional part" (a positive fraction less than one) without any sign between them ("+" is implied, which is an unfortunate exception to the international implicit multiplication rule which says that the mere juxtaposition of two well-formed expressions denotes their product).
To input a number a a mixed fraction on the TI-36X Pro, press [2nd][7] and you'll be prompted for the three relevant integers in 2-dimensional edit mode (integral part, numerator and denominator of the fractional part). Supplying anything but integers will trigger a SYNTAX ERROR. If a negative sign is given before the integral sign, the whole thing is negated (not just the integral part).
To factor into primes an integer with 6 digits or less, type [math] [4] [enter].
Thus, the speed of light (Einstein's constant, c) is obtained by typing:
[ 2nd ] [ constants ] [ 1 ]
The menu that pops up after the first two keystrokes serves as a reminder of what constant is associated with which numeric button (1-9 only, the "0" key is unused). The menu may also be navigated to hightlight the description of a constant whose SI value can then be fetched by pushing the usual [enter] key (bottom-right corner of the keypad). That latter access is mandatory for 11 of the 20 predefined constants.
In the following table, we've given every constant known to the TI-36X Pro an ID from 1 to 20 according to the order of its appearance in the calculator's menu (which only shows IDs below 10). For good measure, we've also listed other physical constants of some importance which have been similarly featured by other calculator manufacturers (or should have).
The standard convention (discussed elsewhere on this site) is that the digits between parentheses that follow a measured quantity indicate its experimental uncertainty (one standard deviation) expressed in units of the least significant digit.
The 20 predefined constants of the TI-36X Pro are based on CODATA 2006.The TI-36X Pro has an internal accuracy of 13 digits, but never displays more than 10 digits. We've followed that convention in the above table, occasionally showing fewer decimals than internally stored.
For clarity, the calculator displays answers with at least a two-space indentation on its regular 16-character line. With two formatting characters (the decimal point and the exponent sign) and a two-digit exponent, there's still enough room to display 10 digits, unless the number itself and/or its exponent sport negative signs, in which case the value must be shown rounded to 8 or 9 significant digits.
The green highlighting in the above table indicates exact constants that have been stored internally at the full nominal 13-digit accuracy of this calculator (and correctly rounded at that internal accuracy, kudos to the Texas Instruments engineers for not being sloppy on that one).
Consider, for example, the value listed above with ten decimals (8.854187818) for the value of the electric constant (a.k.a. the permittivity of the vacuum). Its SI value is known exactly because of the modern definitions of the meter and the ampere. Yet, as it involves a two-digit negative exponent (E-12) the display is rounded to 9 digits (8.85418782). If you multiply that by 1E21 you obtain what appears to be a ten-digit integer (8854187818) but when you subtract 8854187817 from it (keyed in manually) you obtain 0.62 (actually 0.620) which reveals the (correct) 13-digit internal representation of that constant:
8.854187817620 10-12
Likewise, inside the TI-36X Pro, Coulomb's constant is 8987551787.368 and the magnetic constant is 1.256637061436 10-6, with 13 correct digits.
In the following table, the 40 conversions (20 reciprocal pairs) offered by the TI-36X Pro are given a 2-digit ID. The first digit (1-5) is the number of the submenu of the "convert" menu where that conversion appears. The second digit is its rank within that submenu (with the exception of the items numbered from 01 to 20, which are all in the first submenu.)
With the only exception of the two conversion pairs involving the joule (J) in the fifth submenu, the mnemonic rule is that:
To apply this rule, understand that (for instance) kelvins (K) and meters per second (m/s) are, so to speak, more metric than, respectively, degrees Celsius (°C) and kilometers per hour (km/h). I view as a minor bug the violation of this pattern for the two pairs of conversions involving the joule (J) in the fifth conversion screen ("power & energy") where conversions to J should appear in the left column.
The calculator allows you to conjure up a conversion submenu by number (the first digit in the ID, if nonzero) but won't let you execute a specific conversion by using its rank within the submenu (the ID itself or its second digit if 21 or more). It would greatly improve the functionality of the calculator for routine computations if it did (in a future version of the TI-36X Pro, maybe).
That way, someone who regularly uses a specific conversion could simply memorize its code to execute it very quickly. For example, since conversion from pascals to atmospheres is the second item in the fourth submenu, one could conjure it up by punching 2nd-8-4-2. Right now, all you can do is punch 2nd-8-4 to get to the proper submenu, then navigate and select...
Kudos to the TI engineers for getting all of the above conversion factors right at the 13-digit internal precision of their machine (especially the numbers highlighted in green which are often butchered by others). Of course, I can only regret that they followed the lead of other calculator manufacturers in perpetuating the dubious IST conversion factor for the calorie (which is merely derived from the final definition of the Btu, a unit unknown outside the US or UK). The scientific community has been using the 4.184 J/cal conversion factor since 1935.
Cassini Since August 2012, the astronomical unit of length (au) has an exact metric equivalent. Since it's defined as a precise multiple of the astronomical unit, the parsec (pc) too has a freshly minted final equivalent in metric terms which may differ slightly from previous experimental conversion factors (which are now obsolete). We now have:
1 au = 149597870700 m (by definition)
1 pc = 648000 au / p =
3.0856775814913672789... 1016 m
Those conversion factors were enacted so recently that no calculator can be expected to be up-to-date now (and for some time to come). Indeed, the TI-36X Pro actually uses for the parsec a slight 11-digit overshoot of 3.085677581200 1016 m (instead of the correct 13-digit value, which is now 3.085677581491 1016 m). Multiplying this into p / 648000 would give the following approximation for the astronomical unit:
149597870685.8741... (or 149597870685.9 if rounded to 13 digits)
The (outdated) source of that precise number is a mystery to me.
[画像: Come back later, we're still working on this one... ]
To the best of my knowledge, the bug reported elsewhere in September 2011 (about a bad display of multiples of p in "mixed fraction" format) has not been fixed yet. It's still on the calculator I bought in November 2012.
The issue is strictly a display problem which you'll never notice if you keep the factory setting which makes the calculator display any rational number as a plain fraction (the ratio of two integers, which may exceed unity). Even if there was no bug, I'd recommend that you keep it that way. (Never use option "1" on the "math" menu. If you ever do, press "on" and "clear" simultaneously to clear the calculator's memory and tell it, litterally, to forget about mixed fractions.)
If you've not been raised in the US (or, I presume, the UK) you may need to be told that a so-called mixed fraction is what you get when you omit the "+" sign in the sum of a positive integer and a positive fraction below unity. In some countries (including the US) children are indeed taught that this sign is optional. That enables them to read tables and labels where this "convention" is traditionally used (mostly in connection with nonmetric units). That would be fine if people were not also taught that this usage is more or less mandatory, that the "+" sign (which makes everything clear in an international context) is somehow not cool and/or that a fraction whose numerator exceed its denominator (a so-called improper fraction) is a bad citizen. I beg to differ on all counts. By all means, do teach children to decipher the intended meaning of mixed fraction but, please, don't force them to use those things. Also, do tell them that mixed fractions cannot be used within mathematical expressions unless surrounded by parentheses.
The aforementioned bug is very well described in the blog of Nick Weil (2012年01月17日). I recommend that you read Nick's prose rather than just watch the video(s) about the bug. I also recommend that you avoid mixed fractions in any scientific work, with or without the TI-36X Pro calculator!
Videos :
Texas Instruments TI-36X PRO bug error by
Mr. TechLabs (2011年09月29日)
TI Planet
(in French) by Critor (2011年10月07日). In Europe, the calculator is called TI-30X Pro.
TI-36X PRO Programming Bug by
Nick Weil (2012年01月16日).
Pseudo-Bugs: Daniel Hendrycks (2012年05月06日).
