### Entry Level Calculators for High School

2015/08/31

We're talking about school calculators today. Entry level high school calculators to be exact. The kind your kid will need if they're taking general math or sciences. That is to say, the kind you might have to buy this week.

I get that buying your kid a calculator for math or science class is probably not the most pressing spending decision you'll face this fall but it's not exactly a trivial one either. A nice calculator with good documentation could pique your kid's interest in mathematics and might well encourage a curious student to do a little exploration of the subject on their own.

You can buy a scientific calculator for as little as \$2.50 at your friendly neighborhood dollar store these days. By the standards of dollar store electronics, some of them actually aren't that bad, but are they suitable for school?

The so-called "56 function" scientific calculators sold at dollar stores are retro technology. All of them use electronic circuitry that functions in a very similar manner to the Texas Instruments TI-35 Plus, which first appeared on the market in 1986. The original TI-35 Plus was a nice machine in its day but it wasn't designed for the way calculators are presently used in education and offers little to foster an interest and understanding of mathematics.

The next step up - and it's a BIG step - from the 56 function clone is the two-line display calculator. One of these things will typically set you back CDN \$10-\$20 this time of year. This type of calculator is the minimum I'd recommend for school. From what I see on the racks in stores in the market area I live in, it would appear that quite a few educators share my opinion.

Two line scientific calculators have three major advantages over their ancestors.

• They allow one to review and edit calculations. The result of a calculation appears on one line of the display, the equation that produced it on the other. You can go back and edit the equation if the calculation resulted in an error or you want to recalculate the equation with different parameters. Units of this type typically remember the last 20 or so equations you entered and you can scroll through them with arrow keys or a D-pad like you'd find on a video game controller. A 56 function clone cannot display the equation at all, only the answer.

• These devices have an operating system that allows you to enter equations into the machine pretty much the same way you'd write them down on paper. This type of system is known generically as "BASIC data entry mode", meaning equations are keyed into the calculator similar to the way they would be in a computer program written in the BASIC programming language.

• The one-liners don't have much of an operating system at all. You enter a value, press an operator key and a number appears with no hint of what the equation was that produced it.

• Most two-line instruments implement memory as a set of variables rather than the extremely basic single accumulator-type memory found in the older units. Rather than just storing and recalling a numeric value, these calculators associate a value with a variable name that then can be used in equations. The way this is implemented is, again, very similar to the way it would be done in a computer program.

Taken together, these factors make the difference between actually doing math with some level of understanding, and blindly pressing buttons.

My own collection of calculators includes three different units that appear to be designed specifically for the early years of high school: the Casio fx-300MS, the Sharp EL-531, and the Texas Instruments TI-30XIIS.

They all have similar capabilities. They're all ten-digit two-line devices that can do basic math, trigonometry and varying degrees of basic statistics and have between five and nine memory variables to work with. All are solar powered with battery backup. They usually cost between CDN \$15-\$20 and are often heavily discounted this time of year.

None of them are perfect and there are differences between them that are significant enough to influence a buying decision, so let's look at them in more detail.

Overall Impressions:

Casio fx-300MS

The fx-300MS is part of Casio's well segmented range of educational calculators. It's the Toyota Corolla of the calculator market: well-designed, good quality and not particularly exciting. These usually retail for \$12-\$15 CDN and they're quite a good little calc for the money. Casio dominates the educational market in most countries outside of North America and Europe and there's a fair bit of educational material using these devices available online.

I'm guessing this is one of Casio's newer units because it has some features - like adjustable display contrast - that were uncommon several years ago. It's a nicely-styled, very solid-feeling calculator cased in what appears to be high-quality ABS plastic. The unit gives the impression you could drive a car over it without ill effect but I don't think I'll try this with mine.

Sharp EL-531

Sharp and Casio have been in a battle for a piece of the worldwide educational market for years and the result has been some of the best low-cost educational calculators ever produced. The EL-531 meets the fx-300 feature for feature and adds a few of its own. I don't see as much third-party educational material around for these devices but they're pretty good calcs for the money. They were on sale around here for \$9.95 a couple of weeks ago and sold out fast. I paid \$15 CDN for mine.

Sharp completely restyled their entire calculator line a few years ago. They left behind the "swoopy" plastic and irregularly-shaped keys that were in vogue at the time and produced a starkly simple plastic rectangle with little adornment. I like the design of these. They are not, however as solid feeling as the Casios. The case feels like it's made of styrene plastic: fine for normal use but might not fare so well if you drive your car over it.

Texas Instruments TI-30XIIS

Texas Instruments is the gold standard in the marketing of educational calculators and you'll find quite a lot of classrooms equipped with these. Students will sometimes ask for them so they'll have the same type of calculator the teacher is using, which can be a rather significant advantage.

The TI-30XIIS is an older unit and doesn't have the same extensive feature set as the other two. That said, it's a nice calculator with a highly evolved professional-feeling design. At \$17 or so, it's also the most expensive of the lot.

Many educational institutions, as well as TI themselves, produce a large amount of material for these calculators.

Whatever else you can say about the TI-30XIIS, it's a nice-looking calculator that feels high-end in just about every respect. The case is solidly constructed of ABS and has a slick curvaceous design that's comfortable to hold and looks kind of cool. It feels like something designed for nobler tasks than entry-level high school math. The same basic design has been on the market since 1999. TI take the appearance of their products seriously and this one's probably due for a cosmetic redesign soon but I hope they take their time about it.

Keyboard and Display:

Casio fx-300MS

The Casio's keyboard gives little tactile feedback to the user but feels solid and rarely if ever misses a keystroke. The keys are in three different colours so the basic math keys are instantly distinguishable from the trigonometric function keys - a nice feature.

The operating system is partially menu based which means fewer keys that multiple functions. This makes the keyboard labeling relatively uncluttered and less confusing to navigate but you do have to learn which are the menu keys.

Unlike any other calculator in this category, the display contrast is adjustable. The display itself is very easy to read when viewed straight-on but becomes harder to see when the unit is sitting flat on a desk. The display looks big, bold and somewhat "chunky". The alphanumeric top line uses a font that looks slightly "squashed"; not as nice looking as the others.

Sharp EL-531

Like the Casio, the Sharp keyboard has little if any tactile feedback. The keys have a very light touch - they feel like buttons on springs - and are easy to hit by accident. The keys are all the same colour but the various different function groups are distinguished by slight differences in the colour of the labels. Also like the Casio, it seldom misses a keystroke.

The Sharp's operating system makes no use at all of menus for anything other than selecting the operating mode, so every function is available directly off of a key. This means that almost every key has at least three functions, which in turn means the keyboard is thickly festooned with labels. These units have a shiny plastic front panel and keytops and this can make the multitude of tiny labels difficult to read. Eventually you get used to it but it's a daunting beast when you first start using it.

The display is very similar to the Casio's.

Texas Instruments TI-30XIIS

The TI-30XIIS has the best keyboard of the lot. The keys provide positive tactile feedback and are in multiple colours. They require just enough force to discourage accidental keystrokes. This is a highly menu-oriented calculator so no key has more than two functions. Quite a few have only a single function. Hence, the keyboard labeling is simple and clear. The layout is good too: Trig functions together in one row, commonly used math keys arranged in columns, and everything within reach of your thumb. The keyboard is a tad narrower than the other units and appears to be designed for one-handed use.

One thing the TI keyboard lacks is key rollover. Both Casio and Sharp have this feature. Because there's no key rollover, hitting two keys at once generally results in a missed keystroke. On the positive side, the TI's various trig and math keys are somewhat wider less densely laid out than on the other two machines.

The TI-30XIIS's display is very different from the other two units. The fonts used are much lighter in weight. They're not as easy to see as the other units but they look, well, nicer. The multiplication symbol is a computer-like "*" rather than a grade-school "x" and the bottom display line can display fractions with a proper "/" symbol. Overall it's a nice display with a degree of sophistication the other two lack but it's designed to give maximum contrast when sitting on a desk. Viewed straight-on, the display contrast is much lower and it's not adjustable either.

Operating System:

Casio fx-300MS (V.P.A.M)

The fx-300MS has a full algebraic operating system, meaning it knows that, for example, multiplication is done before addition when doing a calculation. It therefore correctly calculates the result of 1+2×3, which happens to be 7, not 9. There are still a few cheap calculators on the market that don't have this feature. The order of operations the device follows is described in detail in the documentation.

What I don't like about this device is that it doesn't require parenthesis to be used when entering functions so it's not true BASIC data entry. For example, "sin(45)" and "sin 45" are both accepted without error. In my opinion, this encourages bad habits that will only have to be unlearned at some point. The unit automatically inserts a space after a function, which to me looks unprofessional.

The Casio has what I consider to be a significant problem. The list of prior calculations is erased when a value is assigned to a memory variable. This negates a lot of the value of having variables in the first place. The prior calculation list is also cleared when the unit is powered off. This is inconvenient but it does make it harder to cheat on a test with the thing since it has to be powered up to retain its prior calculation memory.

Sharp EL-531 (D.A.L.)

Otherwise very similar to the Casio, Sharp's operating system displays numeric inputs on the bottom, or result line, of the display. When you press an operator key, the numbers entered vanish and reappear on the top line along with the operator. It works, but it is somewhat confusing. I personally like the Casio and the TI better.

Like the Casio, the EL-531 does not retain its prior calculation memory when turned off. It also suffers from the same problem where this memory is lost if the value of a variable is changed.

Texas Instruments TI-30XIIS (A.O.S.)

Also equipped with a full algebraic operating system, the TI has a different problem. Its prior calculation memory stores only the equations themselves, not the results of the calculations.

Both of the other units recall both the equation and the result. With these units, the user can browse a range of similar calculations and observe how different parameters affect the result. You can't do this nearly as neatly with the TI-30XIIS.

Its prior calculation memory is retained when the unit is turned off, which I think is an excellent feature. Even better, this memory is retained when a value is assigned to a variable.

Secondary Features:

Casio fx-300MS

For an entry level calculator, the device has a pretty impressive set of statistical functions, if you're into that. A dollar-store special can calculate the mean and standard deviation of a list of numbers - which you have to enter "blind" as there's no way to review and edit them.

The Casio goes well beyond this and can calculate several different types of statistical regressions, including non-linear ones. You can also scroll through and edit your input data using the device's D-pad. I'm not sure how pertinent statistical regression calculations are in high school. I never encountered it until university.

Sharp EL-531

The EL-531 goes head-to-head with the Casio on statistics with a virtually identical set of functions.

As I said earlier, I question the value of advanced statistical capabilities in this type of calculator but as it turns out, the Sharp has another feature of less ambiguous utility.

The EL-531 has facilities for working in alternate number bases. In addition to good old decimal numbers, it can handle basic math and logical functions in base 16, 8,5 and binary (base 2) number systems. These number systems are widely used in computer science and being able to calculate using them makes the EL-531 useful in, among other things, programming, network design and support and even computer hardware design.

A number of other calculators have this capability but this is the only one I'm aware of with it in this price range.

Texas Instruments TI-30XIIS

The TI-30XIIS has much more limited capabilities in the statistics department than either of the others. It can calculate mean and standard deviation on a single-variable dataset, and basic linear regression on a two-variable dataset.

Not very exciting, that, but it still sounds better than calculating standard deviations and regression coefficients the way I did it in university, which often as not was with a slide rule.

Documentation:

Documentation for decent quality calculators is probably a significant part of the cost of the unit. All three of these calculators come with documentation that is reasonably complete, accurate and well illustrated with examples, but generally inconveniently laid out on one or two large sheets of paper. The Casio user guide that covers several different calculator models, a cost-driven measure I particularly dislike.

If you dislike paper, you can download the user guides in pdf format for all three units from the respective manufacturers' web sites.

The bottom line:

If all you need is a calculator that just delivers the basic goods and will likely last forever, the Casio fx-300MS is your tool. It's decidedly uninspired but I think it'd be fine for high school science or general math. It won't take you far in university, but then again, neither will either of the others.

The TI-30XIIS is my own favourite for a bunch of somewhat subjective reasons. I particularly like its keyboard and menu-driven operating system. If you need more than basic statistical functions, though, this is probably not the machine for you.

The Sharp EL-531 is the clear winner in functionality and although I don't get any warm fuzzies from it personally, it's probably the one to have, especially if you can still find one for \$9.95. Its ability to calculate in different number bases comes in very handy if you're into computer science at all. The shiny front panel crowded with key labels is somewhat intimidating but you have to admit, it looks kind of cool.