# 1. Introduction

Subtraction is a fundamental arithmetic operation that we often encounter in daily life and in computational tasks. In this post, we'll explore a basic R program that subtracts one number from another, provided by the user.

R is a versatile language for statistical computing and graphics, R can also be employed for basic programming tasks like this one.

# 2. Program Overview

The objective of the program is to solicit two numbers from the user, subtract the second number from the first, and then display the result.

# 3. Code Program

``````# Prompt the user for the minuend (the number from which another number is to be subtracted)
cat("Enter the first number (minuend): ")

# Prompt the user for the subtrahend (the number to be subtracted)
cat("Enter the second number (subtrahend): ")

# Compute the difference of the two numbers
difference <- minuend - subtrahend

# Display the result
cat("The difference between", minuend, "and", subtrahend, "is:", difference, "\n")
``````

### Output:

```Enter the first number (minuend): 15
Enter the second number (subtrahend): 7
The difference between 15 and 7 is: 8
```

# 4. Step By Step Explanation

1. We initiate the program by using the cat function to display a prompt, asking the user for the minuend.

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

2. The readLines(n=1) function captures one line of input from the user. As this input is a character by default, we employ as.numeric to convert it into a numeric form. This value is then assigned to the minuend variable.

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

3. Using a similar process, we ask the user for the subtrahend and assign its value to the subtrahend variable.

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

4. The subtraction is carried out by deducting the subtrahend from the minuend. The result is stored in the difference variable.

``difference <- minuend - subtrahend``

5. To convey the outcome to the user, the cat function is utilized again. This function concatenates and displays multiple arguments. Here, it combines text and variable values to produce a complete message.

``cat("The difference between", minuend, "and", subtrahend, "is:", difference, "\n")``