### Launching R Console in Windows

In this article, we will learn how to use R as a Calculator. Before using R as a calculator, one needs to launch the R software first. In the Windows Operating system, The R installer will have created an icon for R on the desktop and a Start Menu item. Double-click the *R* icon to start the R Program; R will open the console, to type R commands.

## Table of Contents

### R Prompt

The greater than sing (>) in the console is the prompt symbol. In this tutorial, we will use the R language as a calculator (we will be Using R for the computation of mathematical expressions), by typing some simple mathematical expressions at the prompt (>). Anything that can be computed on a pocket calculator can also be computed at the R prompt. After entering the expression on the prompt, you have to press the Enter key from the keyboard to execute the command.

### Using R as a Calculator

Some examples using R as a calculator are as follows

1 + 2 #add two or more numbers 1 - 2 #Substracts two or more numbers 1 * 2 #multiply two or more numbers 1 / 2 #divides two more more numbers 1 %/% 2 #gives the integer part of the quotient 2 ^ 1 #gives exponentiation 31 %% 7 #gives the remainder after division

These operators also work fine for complex numbers.

Upon pressing the enter key, the result of the expression will appear, prefixed by a number in a square bracket:

1 + 2 # output [1] 54

The [1] indicates that this is the first result from the command.

### Scientific Calculator Type Functions in R

One can also use R as an advanced scientific calculator. Some advanced calculations that are available in scientific calculators can also be easily done in *R* for example,

sqrt(5) #Square Root of a number log(10) #Natural log of a number sin(45) #Trignometric function (sin function) pi #pi value 3.141593 exp(2) #Antilog, e raised to a power log10(5) #Log of a number base 10 factorial(5) #Factorial of a number e.g 5! abs(1/-2) #Absolute values of a number 2*pi/360 #Number of radian in one Babylonian degree of a circle

Remember R prints all very large or very small numbers in scientific notation.

### Order of Precedence/ Operations

The R language also makes use of parentheses for grouping operations to follow the rules for the order of operations. for example

1 - 2/3Â Â #It first computes 2/3 and then subtracts it from 1 (1-2)/3Â Â #It first computes (1-2) and then divides it by 3

The R Language recognizes certain goofs, like trying to divide by zero, missing values in data, etc.

1/0Â Â # Undefined, R tells it an infinity (Inf) 0/0Â Â # Not a number (NaN) "one"/2Â Â # Strings or characters is divided by a number

**Further Reading:** Computing Descriptive Statistics in R