Calculator 2.0 Instructions
This is a free online math/scientific calculator similar to those from TI, Casio, HP and others.
It supports functions for algebra and trigonometry.
Enter a formula either by typing on the keyboard, pressing the buttons on the calculator with the mouse,
or a mixture of both. Type in the formula as you would say it, then press
= or the keyboard
enter key. For example:
| Find the value of the equation: |
|
by pressing the calculator buttons: |
 |
|
|
| The display will show:
|
|
 |
Or type it in on the keyboard using the full function names (see below)
s
q
r
t
(
3
^
2
+
4
^
2
)
enter
Functions
Functions can be entered by
- pressing the function button on the screen with the mouse, for example: sin
- type it in on the keyboard, for example: s i n (.
The table below shows what to type for each function.
The function has an argument which must be in parentheses, for example
tan(12).
When you enter a function from the screen buttons, the first parenthesis is entered for you.
For example when you press the
cos button, it enters "
cos ("
| Function |
Button |
Typed in |
Description |
| Sine |
| sin(x) |
The trigonometry sine function*. |
| Cosine |
 |
cos(x) |
The trigonometry cosine function*. |
| Tangent |
 |
tan(x) |
The trigonometry tangent function*. |
| Arc Sine |
 |
asin(x) |
The trigonometry inverse sine function*. The angle whose sine is x. |
| Arc Cosine |
 |
acos(x) |
The trigonometry inverse cosine function*. The angle whose cosine is x. |
| Arc Tangent |
 |
atan(x) |
The trigonometry inverse tangent function*. The angle whose tangent is x. |
| Square root |
 |
sqrt(x) |
Square root of x. |
| Logarithm |
 |
log(x) |
The log base 10 of x. The power to which you must raise the base (10) to get x. |
| Ten to the power x |
 |
pow(10,x) |
Ten raised to the power x. |
| x squared |
 |
x^2 |
x raised to the power 2. |
| Natural Log |
 |
ln(x) |
The log base e of x. The power to which you must raise the base (e - approximately 2.718) to get x. |
| Exp |
 |
exp(x) |
e (approx 2.718) raised to the power of x. |
| The following functions have no buttons on the calculator. They can be entered by typing them on the keyboard only.
|
| Min |
|
min(a,b) |
Returns a or b whichever is smallest. |
| Max |
|
max(a,b) |
Returns a or b whichever is largest. |
| Abs |
|
abs(x) |
Returns the absolute value of x (always positive) |
| Pow |
|
pow(x,y) |
Returns x raised to the power y. pow(2,3) = 8 |
| Round |
|
round(x) |
Returns x rounded off to the nearest whole number |
| floor |
|
floor(x) |
Returns the highest integer less than or equal to x |
| ceil |
|
floor(x) |
Returns the smallest integer greater than or equal to x |
* Note: The six trigonometry functions will operate in degrees or radians depending on the setting of the control
located just below the display window.
Tan() special note: If you calculate tan(pi/2) it should be an error since the tan of a right angle is undefined.
However, pi in a computer is an approximation, with the result that tan(pi/2) calculates to a very large number instead.
Arithmetic Operators
| Function |
Button |
Typed in |
| Add |
 |
+ |
| Subtract |
 |
- |
| Multiply |
 |
* |
| Divide |
 |
/ |
| Exponent |
 |
^ |
Constants
 |
The three constants keys enter the values at high precision (even if only 3 digits are displayed).
From the top:
- Pi - approximately 3.142.
- e - approximately 2.718..
- Square root of 2. - Approximately 1.414..
|
Scientific notation
Scientific notation (E.G. 1e+3 for 1000) is not supported.
The ANS button
Pressing the
ans button inserts the result from the previous line into the formula.
If entering this from the keyboard, enter the three letters:
a n s.
Not valid on the first entry.
Decimal places displayed
Using this control, you can select how many significant digits are displayed in the results.
This only controls the display.
Internally, all calculations are performed and stored using the maximum possible precision.
For example, with three digits displayed, enter
1
0
÷
3
=
to see the result
3.333. Then press
×
3
=
and you will see that the result is 10, not 9.999.
It controls the number of significant digits after the point.
For example, if the result was 1.002782, and you displayed 3 digits
you get 3 digits after the zeros after the point, or 1.00278.
Trailing zeros are never displayed.
Automatic Features
| Automatic multiplication |
If a function (such as sin() ) is preceded by a number, the calculator assumes you want to multiply them. For example
3cos(2.1) will be automatically treated as if you entered 3*cos(2.1): three times the cosine of 2.1
Note: This feature can mislead you. For example if you enter
1/2sin(.5) the calculator inserts a multiply between the 2 and the sin.
Since there are no parentheses, the calculator executes it from
left to right so it operates as though you meant (1/2)sin(.5).
|
| Automatic chaining |
If the first thing you enter on a line is multiply, divide, add, subtract or exponent, it assumes you want to work
on the the result from the previous line.
For example, if you enter
1 + 1 = and get the answer 2. Then enter
+ 3 =. It will add the 3 to the previous answer and get 5. |
| Automatic parenthesis balancing |
When you press = or enter, it will automatically add enough closing parentheses to balance them.
For example, if you enter
( 4 + 6 =
it will add an extra closing parenthesis and get the answer 10.
Note: This may not always produce the desired result. It is best to always enter the correct expression yourself. |
| Function chaining |
If the last thing on a line is a function with no argument, then it
assumes you want the previous result to used as the argument.
For example, enter
2 + 6 = and get the answer 8. Then enter
sin =. It will find the sine of 8, the previous result. |
Unary minus
To start an expression with a negative number, enter zero first. For example to enter -6+2 enter 0-6+2 instead.
Otherwise, the calculator will assume you want to subtract from the previous result.
Full Screen mode
Click on the button to enlarge the calculator.
A new window will open as large as your monitor will allow, containing a new instance of the calculator.
Press "close" or close the large window in the usual way when you are done with it.
This feature is useful when using a projector.
Keyboard input
The keyboard can be used for entry at the same time as the buttons on
the calculator.
The numbers and operators on the numeric keypad to the right of the
keyboard can also be used.
However, due to a problem with most browsers other than Internet
Explorer, you must first click anywhere on the calculator to allow it to
receive input from the keyboard.
RPN
This does not support RPN (Reverse Polish Notation) used by many HP calculators. It uses the algebraic style used on calculators from such companies as Casio and TI.
