This instruction has been translated from Danish into English.

 Link to MathEditor.com

Instruction for MathEditor.com  

With this math editor, MathEditor.com, you can write both text and mathematical formulas very easily.
And you also can get automatic calculation.
You write the formulas very simply in IT format and the formulas are automatically converted to the mathematical format.
It is very fast to write formulas in IT format. For example, if you want to write   1 
  ,   then just type 1/2.

You enter the upper square above: Half of 10 is 10/2
Then click
or press Enter.
The flags and the text will disapear
and automatically will be written:
Half of 10 is   10
  =   5  

Open MathEditor.com   and try !

MathEditor.com can be operated directly online from the website and can also bedownloaded to your own computer and used offline.

Click button explanation
If you click on a click button, the procedure is as described below.
  MathEditor will be downloaded as a ZIP file named MathEditorOffline. The file is usually stored in the Downloads folder. On a PC, right-click in the file and select "Extract All ...".
A folder with the same name will be created and there is a file named MathEditorOffline in this folder. Clicking on this file will enable MathEditor without using the Internet.
  You can choose whether you want to use decimal point or a decimal comma. with decimal point, commas may not appear in calculation expressions, and with decimal comma, points may not appear in calculation expressions. The desired decimal point is used in the subsequent calculations.
The same effect can also be achieved by using the desired decimal point in a calculation expression.
  You can choose whether angles should be measured in degrees or in pure numbers (radians).
  Calculation will be made.
This facility can also be accessed by pressing "Enter" (line breaks).
  TOTAL is written, and the sum of the values above is displayed, but below a place higher up, where it also says TOTAL. If there is no TOTAL higher up, then the sum of all values above is displayed. The same effect is achieved by typing TOTALE or GESAMT.
  The text in Math format is printed or saved as a PDF file.
If you want to save, change the printer to "Save as PDF". If you want to save the text in IT format, just click:   .
  Here you can send the IT text by e-mail. The recipient can view the math in a mathematical format by copying to MathEditor. It can often make sense to send yourself and then save the IT text for further editing later.
This facility is not available offline.
      Another website will open with MathEditor. It is useful to solve several tasks.
  Some characters are displayed, which can be inserted at the end of your text with one click.

Math expressions and number of decimal places
Arithmetic expressions are written in IT format, which is very fast.
If the result is with more than 2 decimal places, you will be asked how many decimal places you want. The result is then shown.
Subsequently, the number of decimals can be changed by either removing decimals or adding random decimals as decimals and clicking in or press Enter and the random decimals will be replaced with the correct ones.
Be careful about removing decimal places. For example, ½ will be calculated and rounded to 1 at 0 decimal places.
Format of the math IT-Format
  Plus 2 + 3 2+3   There is no difference
  Minus 5-3 5 - 3   There is no difference
  Multiplication 2⋅3
2*3   2·3   when decimal comma is used
  and 2×3 when decimal point (period) is used.  
the sum of above values is calculated.
  Superscript 5^2
  Subscript x2 x_2
  Square root √9 sqrt(9)
  Root ³√7 root(3;7)  Note: Semicolon
  ! 3! = 6 3! = 6  There is no difference
  Pi    π π pi()   π = 3,14 (rounded)
  Euler's number   e e e()   e = 2,718 (rounded)
  Logarithm Log(10)=1 Log(10)=1  There is no difference
  Natural logarithm Ln(e) Ln(e())
  Natural exponential function    exp(e) = 1  exp(e()) = 1 
  Cosine Cos(60°) cos(60)
 Both options are available in the
 IT format can be used
  Sinus Sin(30°) sin(30)
 Both options are available in the
 IT format can be used
  Tangent Tan(45°) tan(45)
 Both options are available in the
 IT format can be used
  The inverted cosine Cos-1(0)
  The inverted sinus Sin-1(1)
  The inverted tangent Tan-1(1)
  Σ   Sigma
Σ 2j = 12
 Sigma(j=1;3;2j) = 12  Note: Semicolon.
 After the sigma comes automatic
 line break in the Math text.
  You can define functions yourself
  with names from a to z and from A to Z.

  Function names are case-sensitive.
  Ie by functions distinguishable
  uppercase and lowercase.

  For example, type:
  G(t)=t^2           (t^2=t²)

  When you define a function, you often
  by automatic calculation also will get
     the derivative and antiderivative,
  as you can use immediately without further ado.

  If you want to see the function expression,
     just enter for example: G(t)
10+g(3) = 16
10+g(3) = 16

Bold, lowered, raised and colored font
Bold are obtained by <<bold >> , Example: <<bold >> a=5 becomes: a = 5
Bold printed shifts are indicated by < nobold >> finished or at the end of the text.
Colors are obtained by <<red>>, <<blue>>, <<brown>>, <<green>> or <<black>>. The color continues the text or until new color is selected.
Finally, font bold also appears after the text "  = "(2 spaces and an equal sign). Therefore, the calculation results are printed in bold.
Lowered font is available by   _   and automatically terminates appropriately.     Example:   b_2*5   becomes  b2*5   and  b_(2*5)  becommes  b(2*5)
Raised writing, eg exponents, is available by  ^  and terminated automatically in appropriate manner    Example:  5^2*5  becomes  5²*5  and  5^(2*5)  becomes  5(2*5)

Insert Table
This is done by typing   ::   (2 colons) between each table element.
If you want calculation of mathematical expressions inside a table element, then write the mathematical expression and get the calculation before writing   ::   . Then you can replace   @   with   =   .

If angles are specified in degrees, it is most beautiful to write ° .  eg: Sin(30°).  
The icon °  will often be supplied automatically.  Anyway you can get   °   by clicking
Futhermore you on a PC can get   °   by holding down the Alt key and pressing 248 on the numeric keypad.

Facit can be remembered
Facit can be remembered in a letter, for example, by typing the following: b=2*3
For example, you can write down the following: b+1 and the value is 7
There is no distinction between uppercase and lowercase letters.

% can be included in the calculation. Example: 4*20% = 0.80

Link to
Learn calculating online