# Rust for the Novice Programmer/Basic Maths Testing Program/Getting Started

## Getting Started with our Maths Program

Let's start a new program by going to a new folder in the terminal and typing 'cargo init'. Then we can open up main.rs in the src/ folder. Let's start off by writing a function to take in the numbers and print out the question to the terminal.

```fn print_question(num1: i32, num2: i32) {
println!("What is {} + {}?", num1, num2);
}
```

And in our main function, we call it like so:

```fn main() {
print_question(35, 23);
}
```

And if we run this now with 'cargo run' we get

```What is 20 + 30?
```

in the terminal.

However, this only works with addition. Let's make it work for both addition and subtraction. To represent the mathematical operator, we need something that can be one of a number of options. The perfect way to represent this is with an enum. So we create our enum as follows:

```enum Operator {
Subtraction,
}
```

Now, to display the operator, we can match against the operator and select the character for it, so we change our print_question() function as follows:

```fn print_question(num1: i32, num2: i32, operator: Operator) {
let operator_string = match operator {
Operator::Subtraction => "-",
};
println!("What is {} {} {}?", num1, operator_string, num2);
}
```

And we can change our main function to:

```fn main() {
print_question(35, 23, Operator::Subtraction);
}
```

And now when we run cargo run, we get

```What is 35 - 23?
```

in the terminal.