Casio FX-P401- User Manual

This suggests 2 − π might be worked out by 2 y x − π or perhaps 2 y x ( − π ) . Neither approach works. It is sensible to do some experiments, to see how a calculator works, and then, understanding it, proceed to the real problem. Once we can do the right sort of thing, we should be able to substitu...

marketted for at least ten years and its serial number suggests it has been revised many times. 4 Calculators have inadequate constants (recall the inconsistent use of π ). The precision of conversions may be unnecessarily different to other calculations on the same calculator. All the calculators t...

3.4 Over-functionality Buttons mean lots of different things. Button with four meanings, depending on the mode, are common.Many of the calculators (especially the Texas Instruments and Casio mo dels) have low legibility andpoor colour coding schemes, which exacerbate problems with overloaded buttons...

evidently means 4 − 5. But if there is a ‘correction rule,’ it does not generalise: 8 3 √ √ takes a 6th. root, not a square root; and 2 + + 3 creates an ‘add 2’ mode ( § 3.5). Understo od like this, operator correction is just another feature intro ducing spurious complexity and still failing to sol...

according to the rules of arithmetic .” [24] The purp ose of a calculator is to do correct calculations, and to do so efficiently. It is clear thata calculator should relieve the user of the need to do mental operations and of the need to rely onpaper, so far as possible. Calculators (and their manu...

Key press Display after each key press 4 × − 5 ∆ = − 20 ⇐ 4 × − ∆ 5 = − 20 DEL 4 × ∆ 5 = 20 = 4 × 1 . 25 = ∆ 5 8 4 × 21 . 25 = 8 ∆ 5 ⇒ 4 × 21 . 25 = 85 ∆ DEL 4 × 2 = 8 ∆ DEL 4 × 1 = ∆ 4 Figure 4: Example of editing a simple calculation. The changes to the display occur immediately, on every key pres...

you can, and what’s more you only need to input the formula once, thereafter you can just fillin the knowns and the calculator works out the unknown. So then he says: “WHY AREN’TALL CALCULATORS BUILT LIKE THAT?” [25] Showing a key-by-key description is tedious and obscures the clarity of this calcul...

Key press Display after each key press 33 . 8 ∆ = 1 × 1 . 8 + 32 − − ∆ − 33 . 8 = 1 × 1 . 8 + 32 4 − 4 ∆ = − 20 × 1 . 8 + 32 0 − 40 ∆ = − 40 × 1 . 8 + 32 Figure 5: Converting Fahrenheit and Celsius. We continue with the calculation (described in the text) just after deleting the 100 and 212, so the ...

Problem New calculator Casio fx -82 lb ‘fraction’ calculator 4 / 3 =? 4 / 3 = 1 + 1 / 3 4 a bc 3 = , answer: 1 1 3 1 . 1 =? 1 . 1 = 11 / 10 = 1 + 1 / 10 cannot handle decimals (4 / 3) 2 =? (4 / 3) ↑ 2 = 16 / 9 cannot handle squares Figure 6: Calculating with fractions. The user can obtain more detai...

An important property of RCL is that whenever the memory is used its value can be seen (this is not the case on any other calculator reviewed here). The two immediately successive key presses S T O RC L when the cursor is in a correction have a combined effect identical to FIX , though also changing...

or to b eep and not change the display? 9 (The keyboard has a key e so that large numbers can be entered exactly as they are displayed.) The prototype calculator takes the approach that, if possible, no user action should b e discarded. Thus we get the longer correction to huge factorials. The appro...

7.9 Other important design details Current calculators can be criticised on their non-technical design. A good calculator would b e ruinedby p oor design. The following points may seem obvious when they are stated explicitly, but severalcalculators get details wrong. The keys will have a firm resp o...

log 10 (3) + log 10 (4) = log 10 (12) 10 ↑ log 10 (42) = 42 71 × log 10 (10) = log 10 (10 ↑ 71) 2000 = 3 + log 10 (2) Figure 7: The calculator as a ‘chalk board.’ The user can edit the equations and see the numerical identities, even when the base of the logarithm is changed. Note the effective use ...

8.6 Non-specific complaints My final resp onse to ob jections is that the new design is mathematical. It is mathematical in twoimportant ways that no other calculator is. It is declarative. It is general. Mathematics itself is declarative, meaning its notation is used to express (declare) facts whos...

It may be desirable to introduce mo des for working in degrees, changing the logarithm base, or setting other preferences. This can be done consistently with the rest of the design, though the prototype uses menus for this purp ose. We might introduce a button m and a status (mode) line in the displ...

into algebra rather than numerical coincidences, would cause more educational damage than the cal-culators we are trying to supercede. (That wouldn’t stop it selling.) Compare our brief exploration ofEuclid ( § 6.1) with Euclid’s own exposition of 300 bc . Euclid proves a proposition is true for all...

[11] P. Latham and P. Truelove (1983) Nuffield Maths 3, Pupil’s Book , Longman. [12] R. E. Mayer and P. Bayman (1981) “Psychology of Calculator Languages: A Framework for De- scribing Users’ Knowledge,” Communications of the ACM , 24 (8), pp511-520. [13] G. Polya (Combined Edition, 1981) Mathematica...

' & $ % 22 / 7 ∆ − π = 0 . 001264 → ⇐ F I X DE L ⇒ ( √ π ) 7 8 9 ÷ 4 5 6 × 1 2 3 − 0 • = + Figure 8: The new calculator — example key layout. The calculator has a protective flip cover with a quick reference list, explaining, in particular, the buttons FIX , DEL , ⇐ , ⇒ , the display’s ∆ symbol ...