"Blackboard" Calculator

Arithmetic operations and elementary functions

Everything becomes clear if you type = 2+3 in the calculator window and click the "Start" button. The formula you enterule will remain unchanged, but the number 5 will appear below it. This is the result of the calculations.

Rule 1. An equal sign that precedes an arithmetic expression indicates to the calculator that the expression is to be evaluated.

For example, the expression 2+3 after pressing the "Start" button is not calculated, and instead of the result, an error message appears.

Arithmetic operations and brackets can be used in expressions, and elementary functions and constants shown in Table 1 are available for scientific calculations. The author tried to bring formulas as close as possible to the "school" style.


  • Clicking the "Start" button is equivalent to pressing the F5 key.
  • Before recalculating after making changes, the results of previous calculations do not need to be deleted - they are deleted automatically
  • You can completely clear the calculator window using the "New" menu item in the "File" menu or the keyboard combination Ctrl+N.
  • Using the adjacent text box, you can set the number of decimal places to display. Valid values ​​range from 0 to 15.

Таблица 1. Арифметические операции, постоянные и элементарные функции

Arithmetic operations and constants Functions
Addition a+b Trigonometric functions sin(), cos(), tg(), ctg()
Subtraction a-b Inverse trigonometric functions arcsin(), arccos(), arctg(), arcctg()
Multiplication a*b Exponential functions exp(), sh(), ch()
Division a:b or a/b The natural logarithms and decimal ln(), lg()
Exponentiation a^b Square root extraction sqrt()
Parentheses (), [], {} Rounding to integer round()
Number "pi" pi=3.14... Pseudo-random integer from 0 to n random(n)
Euler's number e=2,71... Absolute value (module) |a|



  • By applying functions to numbers (but not to expressions!), parentheses can be omitted. For example, lg0.17.
  • The same is true if the function argument - a number or expression - is under the sign of the module. For example, lg|1+2|.
  • The decimal separator can be either a comma or a period.
  • For speed dialing, you can use function templates by clicking the "Function Templates" button. In the list that appears, select the required template - it will appear in the calculator window in the place indicated by the cursor.