## DEV Community # Scilab: A Beginner's Guide to Basic Commands I

Welcome back to our series on Scilab! We apologize for the break in the course, but I'm excited to get back to it and continue learning about this powerful software.

## Declaring Variables and Performing Basic Arithmetic Operations in Scilab

In Scilab, we can declare variables and perform basic arithmetic operations just like in any other programming language. However, unlike some languages, we don't need to explicitly declare variables before using them. This is because Scilab is an interpreted language, which means that it processes and executes code on the fly rather than compiling it beforehand.

To declare a variable, we simply assign it a value using the assignment operator `=`. For example:

``````--> x = 5
--> y = 10
``````

Note that in Scilab, we don't need to use a semicolon (;) at the end of a statement when declaring variables or defining functions. This is optional, but it's a good idea to use them to help improve the readability of your code.

We can then use these variables in arithmetic expressions to perform operations such as addition, subtraction, multiplication, and division. Here are some examples:

``````--> x + y
15.
--> x - y
-5.
--> x * y
50.
--> x / y
0.5
``````

Note that Scilab follows the standard order of operations, so we can use parentheses to specify the order in which operations should be performed. For example:

``````--> (x + y) * (x - y)
-75.
``````

In addition to the basic arithmetic operators, Scilab also provides a number of functions for performing more advanced mathematical operations. For example, we can use the `sqrt` function to calculate the square root of a number:

``````--> sqrt(25)
5.
``````

To perform exponentiation (raise a number to a power), we can use the `^` operator. For example:

``````--> x ^ y
9765625.
``````

We can also use the log function to calculate the natural logarithm of a number:

``````--> log(10)
2.302585092994046
``````

A more advanced and detailed list of scilab functions/operations can be checked in the Scilab Documentation.

With these basic skills under your belt, you're ready to start writing simple programs in Scilab. Remember that this is only the first of three parts, so be sure to stay tuned for the next installment, where we'll cover more advanced topics that will be crucial for continuing your journey with Scilab.