# 1. Introduction

One of the basic operations in any programming language is arithmetic computation. In this post, we'll walk through a simple R program that adds two numbers provided by the user. R, known for its powerful statistical and data visualization capabilities, can also be used for basic programming exercises.

# 2. Program Overview

The program will prompt the user to input two numbers. It will then compute the sum of these numbers and display the result.

# 3. Code Program

``````# Prompt the user for the first number
cat("Enter the first number: ")

# Prompt the user for the second number
cat("Enter the second number: ")

# Compute the sum of the two numbers
sum <- number1 + number2

# Display the result
cat("The sum of", number1, "and", number2, "is:", sum, "\n")
``````

### Output:

```Enter the first number: 5
Enter the second number: 3
The sum of 5 and 3 is: 8
```

# 4. Step By Step Explanation

1. We start by using the cat function to display a prompt message to the user, asking for the first number.

``cat("Enter the first number: ")``

2. The readLines(n=1) function reads one line of input from the user. Since user input is treated as a character string, we use as.numeric to convert this input into a numeric value, which is then stored in the variable number1.

``number1 <- as.numeric(readLines(n=1))``

3. Similarly, we prompt the user for the second number and store it in the variable number2.

``````cat("Enter the second number: ")

4. We then compute the sum by adding number1 and number2 and store the result in the sum variable.

``sum <- number1 + number2``

5. Finally, we use the cat function again to display the result. The cat function can take multiple arguments and will concatenate them. Here, we're displaying a message that combines text with the values of our variables to inform the user of the result.

``cat("The sum of", number1, "and", number2, "is:", sum, "\n")``