Version: | 1.14.549 |
---|---|
Date: | 2018-09-14 19:29 UTC |
Organization: | National Braille Press |
Contact: | Brian Mac Donald |
Address: | 88 St. Stephen Street Boston, MA 02115 United States of America |
Contents
This calculator has been designed to be as usable as possible not only by sighted people but also by blind people using speech and/or a braille device. It's easy to use via it's own on-screen calculator-style keys, a full on-screen keyboard, or an externally-connected Bluetooth or USB keyboard.
It offers the following features:
This subsection contains screen layout images that've been intentionally drawn using traditional ASCII art. This has been done so that a blind person can easily "look" at them because screen readers are notoriously poor at dealing with graphical images.
In both portrait and landscape modes, the result line is immediately above the expression line and the Clear button is immediately below it at the very left. This is to make expression entry as easy as possible for a blind person using a braille device. Moving backward one position enables him/her to quickly check the result, and moving forward one position allows him/her to easily clear the expression.
Layout Legend
AltKp | Alternate Keypad selector |
AUSel | Angle Unit selector |
BkSpc | Backspace button |
Clear | Clear button |
CMSel | Calculator Mode selector |
Del | Delete button |
DNSel | Decimal Notation selector |
Down | Down button |
Erase | Erase button |
f(x) | f(x) button |
Left | Left button |
Right | Right button |
Store | Store button |
Up | Up button |
Var | Variable button |
The screen has the following layout when in portrait mode:
+---------------------------------------+ | The Result Output Area | +---------------------------------------+ | The Expression Input Area | +-------+-------+-------+-------+-------+ | Clear | AltKp | CMSel | DNSel | AUSel | +-------+-------+-------+-------+-------+ | Var | Store | BkSpc | Up | Del | +-------+-------+-------+-------+-------+ | f(x) | Erase | Left | Down | Right | +-------+-------+-------+-------+-------+ | | | | | The Currently Selected Keypad | | | | | +---------------------------------------+
The screen has the following layout when in landscape mode:
+-------------------------------------------------------+ | The Result Output Area | +-------------------------------------------------------+ | The Expression Input Area | +-------+-------+-------+-------------------------------+ | Clear | AltKp | CMSel | | +-------+-------+-------+ | | DNSel | Var | Store | | +-------+-------+-------+ | | AUSel | f(x) | Erase | The Currently Selected Keypad | +-------+-------+-------+ | | BkSpc | Up | Del | | +-------+-------+-------+ | | Left | Down | Right | | +-------+-------+-------+-------------------------------+
This output area displays the on-going current result of evaluating what's been entered in the expression line. If no data has been entered yet then 0 is displayed. If the expression can't be evaluated at the moment (e.g. due to missing data or syntax errors) then the last known result, preceded by a question mark [?], is displayed. The displayed value begins with zero or more open brackets [(] - one for each bracket nesting level that hasn't yet been closed. Expression evaluation only considers the current bracket nesting level.
To illustrate, here's what's displayed as the expression (2+3)×(4−(5+6)×7) is entered:
Expression | Result |
---|---|
0 | |
( | (? |
(2 | (2 |
(2+ | (?2 |
(2+3 | (5 |
(2+3) | 5 |
(2+3)× | ?5 |
(2+3)×( | (?5 |
(2+3)×(4 | (4 |
(2+3)×(4− | (?4 |
(2+3)×(4−( | ((?4 |
(2+3)×(4−(5 | ((5 |
(2+3)×(4−(5+ | ((?5 |
(2+3)×(4−(5+6 | ((11 |
(2+3)×(4−(5+6) | (−7 |
(2+3)×(4−(5+6)× | (?−7 |
(2+3)×(4−(5+6)×7 | (−73 |
(2+3)×(4−(5+6)×7) | −365 |
This input area is where the expression to be evaluated is entered (see Expressions for syntax). It's current content is persistent.
The expression can be entered by pressing the calculator-style keys on the screen, via a full on-screen keyboard (tap this line to open it), or via an external keyboard. Additionally, the navigation buttons can be used to edit the expression.
The result of evaluating the expression is displayed on the result line. It's kept up-to-date as the expression is being entered and/or edited.
Typing this key completes the expression. The expression is added to the expression history, the expression line is cleared, and the final result is displayed on the result line. If there's an error then the cursor is placed at the error's location and the message is displayed on the result line.
Pressing the = key on any of the keypads performs this same action.
the following actions can be performed by typing shortcuts on a keyboard:
Character | Action |
---|---|
CTRL-A | Long press the Angle Unit selector. |
CTRL-C | Press the Clear button. |
CTRL-D | Press the Down button. |
CTRL-E | Press the Erase button. |
CTRL-F | Press the f(x) button. |
CTRL-K | Set the input focus to the Keypad. |
CTRL-M | Long press the Calculator Mode selector. |
CTRL-N | Long press the Decimal Notation selector. |
CTRL-S | Press the Store button. |
CTRL-U | Press the Up button. |
CTRL-V | Press the Variable button. |
A history of successfully completed expressions is maintained. An expression is considered complete if there are no syntax errors within it when either the = key on any of the keypads is pressed or when the Enter key is typed.
Any history entry can be edited and recompleted, although the history entries themselves are never actually changed. Edits to an entry are lost when moving away (up or down) from it without recompleting it. Recompleting a history entry adds it as a new entry.
Pressing this button clears the expression line.
Repeatedly pressing this button cycles through all of the keypads associated with the current calculator mode. A long press switches to the mode's primary keypad. This button is disabled if the mode only has one keypad.
Repeatedly pressing this button cycles through all of the calculator modes. A long press presents a list from which the desired mode can be selected. The button's label is a three-letter abbreviation for the current selection. The current selection is persistent.
The following modes are available:
Decimal (the default). This mode performs real and complex operations on IEEE 64-bit floating-point (commonly known as double) values. They consist of a 1-bit sign, an 11-bit exponent, and a 52-bit significand. Other than 0 (which is a special case), the smallest absolute value that this representation supports is 2^{-1074} or approximately 5×10^{−324}, and the largest absolute value that it supports is 2^{1023} or approximately 1.8×10^{308}. Calculations are performed with an accuracy of 15 significant digits.
This mode supports complex numbers. The imaginary component, if nonzero, is displayed as either an addition to or a subtraction from the real component. If a number doesn't have an imaginary component then only its real component is displayed. If it does have an imaginary component but doesn't have a real component then only the imaginary component is displayed. Here are some examples:
The keypads associated wit this mode are:
Hexadecimal. This mode performs unsigned integer and bitwise operations on 64-bit values. Both input and output are in base 16 and use hexadecimal digits. Digits A through F are always displayed in uppercase but may be input in either case. A number may consist of up to 16 hexadecimal digits.
The keypads associated wit this mode are:
Repeatedly pressing this button cycles through all of the decimal notations. A long press presents a list from which the desired notation can be selected. The button's label is a three-letter abbreviation for the current selection. The current selection is persistent.
The following notations are available:
Fixed (the default). If the absolute value of the number is less than 10^{12} [1,000,000,000,000] and greater than or equal to 10^{-3} [0.001] then it's displayed with its decimal point in its natural position. Its power of ten multiplier (e.g. ×10^{x}) isn't displayed (because it's 0), and digit grouping separators (e.g. 1,000) are displayed (to ease readability). If the number is an integer then the decimal point isn't displayed.
If the number is outside this range then it's considered to be too difficult to intuitively read in fixed notation, and scientific notation is used instead.
In all cases, the sign is only displayed if the number is negative. This is also true for the power of ten.
Fixed | 0.0123 | 456,789 |
Scientific | 1.23×10^{-2} | 4.56789×10^{5} |
Engineering | 12.3×10^{-3} | 456.789×10^{3} |
Repeatedly pressing this button cycles through all of the trigonometric angle units. A long press presents a list from which the desired unit can be selected. The button's label is a three-letter abbreviation for the current selection. The current selection is persistent.
The following units are available:
These keys provide easy access to the predefined variables and to the predefined functions. They can also be used to manage user-defined variables.
Var | Store |
f(x) | Erase |
Pressing this button presents a list of the user-defined variables followed by the predefined variables. Each line contains the name and current value of a variable. For a predefined variable, it also contains its description.
Selecting a variable from this list enters its name into the expression line. The following actions are also available:
Pressing this button presents a list of the user-defined variables. Each line contains the name and current value of a variable.
Selecting a variable from this list assigns the value currently shown on the result line to it. The following actions are also available:
Present a dialog for entering the name of a new variable. This dialog doesn't allow an existing variable to be overwritten. It offers the following actions:
Variables can also be created or updated via the = operator within an expression. For example:
To clarify: the last example sets z to 5, y to 9, and x to 12.
Pressing this button presents a list of the user-defined variables. Each line contains the name and current value of a variable.
Selecting a variable from this list removes its definition. The following actions are also available:
A long press presents the same list in a way that allows several variable definitions to be removed at once. It offers the following additional actions:
Pressing this button presents a list of the predefined functions. Each line contains the name and description of a function.
Selecting a function from this list enters its name, followed by an open bracket, into the expression line. The following actions are also available:
This is the primary keypad for the Decimal calculator mode. It has the following layout:
( | ) | " | ' | x⋅10^{y} |
7 | 8 | 9 | ÷ | x^{y} |
4 | 5 | 6 | × | ! |
1 | 2 | 3 | − | % |
. | 0 | i | + | = |
Most of these keys enter whatever their label says into the expression line. The exceptions are:
The " and ' keys are for entering a number in the degrees"minutes'seconds format. Each of these components ("minutes and 'seconds) is optional. If specified, it's value must be an integer that's greater than or equal to 0 and less then 60. If omitted, it's value is assumed to be 0. If any of these components is specified then a decimal point may not be used.
This is the second keypad for the Decimal calculator mode. It has the following layout:
abs | arg | cnj | rcp |
sin | cos | tan | r2d |
asin | acos | atan | d2r |
sinh | cosh | tanh | sqrt |
exp | log | log10 | cbrt |
e | pi |
Each of these keys enters its function's name, followed by an open bracket [(], into the expression line. The exceptions are e and pi, which don't enter the open bracket because they're variables.
This is the third keypad for the Decimal calculator mode. It has the following layout:
Type | From | To | DF2DC |
Type | From | To | mi2km |
Type | From | To | ac2ha |
Type | From | To | cup2ml |
Type | From | To | lb2kg |
Each four-key row is a separate key group. This allows five different unit conversions to be configured. Each of them, as shown above, defaults to a common US-to-International unit conversion.
The first three keys configure the conversion:
The rightmost key is for actually performing the currently configured unit conversion. It's label shows what that conversion is in the form from2to (e.g. mi2km). This is the name of the predefined function that performs the conversion. Just like the keys on the Function keypad, pressing this key enters the name of this function, followed by an open bracket [(], into the expression line.
Any of the unit conversion functions can be directly typed into the expression line. Because there are so many, none of them is included within the list presented by pressing the f(x) button.
The most recently configured conversion for each unit type for each key group is persistent.
This is the primary keypad for the Hexadecimal calculator mode. It has the following layout:
( | ) | < | > | % | ^ |
C | D | E | F | ÷ | | |
8 | 9 | A | B | × | & |
4 | 5 | 6 | 7 | − | ~ |
0 | 1 | 2 | 3 | + | = |
Each of these keys enters whatever its label says into the expression line. The 0 through 9 and A through F keys are the 16 hexadecimal digits. The rest of the keys are as follows:
Key | Description |
---|---|
= | expression completion |
( | open bracket |
) | close bracket |
< | logical left shift |
> | logical right shift |
& | bitwise and |
| | bitwise inclusive or |
^ | bitwise exclusive or |
~ | bitwise ones complement |
+ | integer addition |
− | integer subtraction or bitwise twos complement |
× | integer multiplication |
÷ | integer division |
% | integer remainder |
Name | Value | Description | Units |
---|---|---|---|
gamma | 0.57721566490153286060 | Euler-Mascheroni constant | |
pi | 3.14159265358979323846 | ratio of circumference to diameter | |
sigma | 5.670367×10^{−8} | Stefan-Boltzmann constant | W m^{−2} K^{−4} |
c | 299,792,458 | speed of light in vacuum | m s^{−1} |
e | 2.71828182845904523536 | base of natural logarithms | |
h | 6.626070040×10^{−34} | Planck constant | J s |
i | i | imaginary unit | |
k | 1.38064852×10^{−23} | Boltzmann constant | J K^{−1} |
F | 96,485.33289 | Faraday constant | C mol^{−1} |
G | 6.67408×10^{−11} | Newtonian constant of gravitation | m^{3} kg^{−1} s^{−2} |
L | 6.022140857×10^{23} | Avogadro constant | mol^{−1} |
R | 8.3144598 | molar gas constant | J mol^{−1} K^{−1} |
Name | Description |
---|---|
abs(z) | absolute value (modulus, magnitude) of complex number |
acos(x) | trigonometric arc cosine |
acot(x) | trigonometric arc cotangent |
acsc(x) | trigonometric arc cosecant |
arg(z) | arg (amplitude, phase) of complex number |
asec(x) | trigonometric arc secant |
asin(x) | trigonometric arc sine |
atan(x) | trigonometric arc tangent |
cbrt(z) | cube root of complex number |
ceil(x) | round real number up to nearest integer |
cnj(z) | conjugate of complex number |
cos(x) | trigonometric cosine |
cosh(x) | hyperbolic cosine |
cot(x) | trigonometric cotangent |
coth(x) | hyperbolic cotangent |
csc(x) | trigonometric cosecant |
csch(x) | hyperbolic cosecant |
d2r(x) | convert real number from degrees to radians |
exp(z) | natural exponential of complex number |
floor(x) | round real number down to nearest integer |
gamma(z) | gamma function of complex number |
imag(z) | imaginary component of complex number |
log(z) | natural log of complex number |
log10(z) | log_{10} of complex number |
neg(z) | negation of complex number |
r2d(x) | convert real number from radians to degrees |
rcp(z) | reciprocal of complex number |
real(z) | real component of complex number |
round(x) | round real number to nearest integer |
sec(x) | trigonometric secant |
sech(x) | hyperbolic secant |
sin(x) | trigonometric sine |
sinh(x) | hyperbolic sine |
sqrt(z) | square root of complex number |
tan(x) | trigonometric tangent |
tanh(x) | hyperbolic tangent |
Symbol | Name | Calculation |
---|---|---|
rad | radians | |
brad | binary radians | 1÷128 = 0.0078125 radians |
deg | degrees | pi÷180 = 0.0174533 radians |
rev | revolutions | 360 degrees |
crev | centirevolutions | 360÷100 = 3.6 degrees |
mrev | millirevolutions | 0.1 centirevolutions |
quad | quadrants | 360÷4 = 90 degrees |
sxt | sextants | 360÷6 = 60 degrees |
oct | octants | 360÷8 = 45 degrees |
sign | signs | 360÷12 = 30 degrees |
point | points | 360÷32 = 11.25 degrees |
hxct | hexacontades | 360÷60 = 6 degrees |
dmin | arc minutes | 1÷60 = 0.0166667 degrees |
dsec | arc seconds | 1÷60 = 0.0166667 arc minutes |
gon | gradians | 0.9 degrees |
gmin | centesimal minutes | 0.01 gradians |
gsec | centesimal seconds | 0.01 centesimal minutes |
Symbol | Name | Calculation |
---|---|---|
m2 SI | meters^{2} | |
a | ares | 100 meters^{2} |
ha | hectares | 100 ares |
sqin | square inches | 2.54^{2} = 6.4516 centimeters^{2} |
sqft | square feet | 12^{2} = 144 square inches |
sqyd | square yards | 3^{2} = 9 square feet |
sqrd | square rods | 5.5^{2} = 30.25 square yards |
sqch | square chains | 4^{2} = 16 square rods |
sqlink | square links | 0.01^{2} = 10^{−4} square chains |
sqfur | square furlongs | 10^{2} = 100 square chains |
sqmi | square miles | 8^{2} = 64 square furlongs |
sqlg | square leagues | 3^{2} = 9 square miles |
ro | roods | 40 square rods |
ac | acres | 4 roods |
Symbol | Name | Calculation |
---|---|---|
J SI | joules | |
erg | ergs | 100 nanojoules |
Ry | rydbergs | 2.179872 attojoules |
eV | electronvolts | 160.217653 zeptojoules |
Ha | hartrees | 27.2107 electronvolts |
ftlbf | foot pounds force | 1.3558 joules |
BTU | British thermal units | 1055 joules |
thm | therms | 100,000 British thermal units |
hphr | horsepower hours | 2.6845 megajoules |
gasgal | gasoline gallons | 120 megajoules |
kWh | kilowatt hours | 3.6 megajoules |
cal | small calories | 4.184 joules |
Cal | large calories | 1,000 small calories |
Symbol | Name | Calculation |
---|---|---|
N SI | newtons | |
dyn | dynes | 10 micronewtons |
sn | sthènes | 1 kilonewton |
kgf | kilograms force | 9.80665 newtons |
lbf | pounds force | 4.4482216152605 newtons |
kip | kips | 1000 pounds force |
pdl | poundals | 0.138254954376 newtons |
Symbol | Name | Calculation |
---|---|---|
m SI | meters | |
in | inches | 2.54 centimeters |
ft | feet | 12 inches |
yd | yards | 3 feet |
rd | rods | 5.5 yards |
ch | chains | 4 rods |
link | links | 0.01 chains |
fur | furlongs | 10 chains |
mi | miles | 8 furlongs |
lg | leagues | 3 miles |
Symbol | Name | Calculation |
---|---|---|
g SI | grams | |
t | tonnes | 1 megagram |
Da | daltons | 1.660539040 yoctograms |
oz | ounces | 28.34952 grams |
dr | drams | 1÷16 ounces |
lb | pounds | 16 ounces |
stone | stones | 14 pounds |
quarter | quarters | 2 stone |
hw | hundredweight | 4 quarters |
tl | long tons | 20 hundredweight |
ts | short tons | 2,000 pounds |
ct | carats | 200 milligrams |
gr | grains | 64.79891 milligrams |
dwt | penny weight | 24 grains |
ozt | troy ounces | 20 penny weight |
lbt | troy pounds | 12 troy ounces |
Symbol | Name | Calculation |
---|---|---|
W SI | watts | |
hp | mechanical horsepower | 745.69987158 watts |
bhp | boiler horsepower | 9,809.5 watts |
ehp | electrical horsepower | 746.0 watts |
mhp | metric horsepower | 735.49875 watts |
Symbol | Name | Calculation |
---|---|---|
Pa SI | pascals | |
at | technical atmospheres | 98.0665 kilopascals |
atm | standard atmospheres | 101,325 pascals |
Torr | torrs | 1÷760 = 1.315789×10^{-3} standard atmospheres |
bar | bars | 100,000 pascals |
psi | pounds per square inch | 6.894757 kilopascals |
mmHg | millimeters of mercury | 133.322387415 pascals |
inHg | inches of mercury | 25.4 millimeters of mercury |
Symbol | Name | Calculation |
---|---|---|
mps SI | meters per second | |
kmph | kilometers per hour | 1,000 ÷ (60 × 60) |
mph | miles per hour | (2.54 × 12 × 5,280) ÷ 100,000 |
Symbol | Name | Calculation |
---|---|---|
DC | degrees Celsius | |
K | kelvins | degrees Celsius + 273.15 |
DF | degrees Fahrenheit | degrees Celsius × 5 ÷ 9 + 32 |
DR | degrees Rankine | kelvins × 5 ÷ 9 |
DRé | degrees Réaumur | 1.25 degrees Celsius |
DRø | degrees Rømer | 100÷52.5 = 1.90476 degrees Celsius + 7.5 |
DDe | degrees Delisle | −2÷3 = −0.666667 degrees Celsius + 150 |
DN | degrees Newton | 100÷33 = 3.0303 degrees Celsius |
Symbol | Name | Calculation |
---|---|---|
s, sec SI | seconds | |
min | minutes | 60 seconds |
hr | hours | 60 minutes |
da | days | 24 hours |
wk | weeks | 7 days |
sen | sennights | 7 days |
fort | fortnights | 14 days |
yr | years | 365.2422 days |
dec | decades | 10 years |
cen | centuries | 100 years |
mil | millennia | 1000 years |
Symbol | Name | Calculation |
---|---|---|
m3 SI | meters^{3} | |
cc | cubic centimeters | 1 centimeters^{3} |
l SI | liters | 1 cubic centimeter |
tsp | teaspoons | 4.92892 milliliters |
tbsp | tablespoons | 3 teaspoons |
floz | fluid ounces | 2 tablespoons |
cup | cups | 8 fluid ounces |
pt | pints | 2 cups |
qt | quarts | 2 pints |
gal | gallons | 4 quarts |
cbin | cubic inches | 2.54^{3} = 16.3871 centimeters^{3} |
cbft | cubic feet | 12^{3} = 1728 cubic inches |
cbyd | cubic yards | 3^{3} = 27 cubic feet |
cbrd | cubic rods | 5.5^{3} = 166.375 cubic yards |
cbch | cubic chains | 4^{3} = 64 cubic rods |
cblink | cubic links | 0.01^{3} = 10^{−6} cubic chains |
cbfur | cubic furlongs | 10^{3} = 1,000 cubic chains |
cbmi | cubic miles | 8^{3} = 512 cubic furlongs |
cblg | cubic leagues | 3^{3} = 9 cubic miles |
Any of these symbols may be prepended to the symbol for any metric unit, and any of these names may be prepended to the name for any metric unit. The metric units within the unit tables are flagged with SI [Système International].
Name | Symbol | Short Scale | Long Scale | |
10^{1} | deca | da | ten | ten |
10^{2} | hecto | h | hundred | hundred |
10^{3} | kilo | k | thousand | thousand |
10^{6} | mega | M | million | million |
10^{9} | giga | G | billion | milliard |
10^{12} | tera | T | trillion | billion |
10^{15} | peta | P | quadrillion | billiard |
10^{18} | exa | E | quintillion | trillion |
10^{21} | zetta | Z | sextillion | trilliard |
10^{24} | yotta | Y | septillion | quadrillion |
Note
u (rather than µ) is being used for micro.
Name | Symbol | Short Scale | Long Scale | |
10^{−1} | deci | d | tenth | tenth |
10^{−2} | centi | c | hundredth | hundredth |
10^{−3} | milli | m | thousandth | thousandth |
10^{−6} | micro | u | millionth | millionth |
10^{−9} | nano | n | billionth | milliardth |
10^{−12} | pico | p | trillionth | billionth |
10^{−15} | femto | f | quadrillionth | billiardth |
10^{−18} | atto | a | quintillionth | trillionth |
10^{−21} | zepto | z | sextillionth | trilliardth |
10^{−24} | yocto | y | septillionth | quadrillionth |
Name | Symbol | |
2^{10} | kibi | Ki |
2^{20} | mebi | Mi |
2^{30} | gibi | Gi |
2^{40} | tebi | Ti |
2^{50} | pebi | Pi |
2^{60} | exbi | Ei |
2^{70} | zebi | Zi |
2^{80} | yobi | Yi |