## Introduction

Swift supports the four standard arithmetic operators:

- Addition +
- Subtraction -
- Multiplication *
- Division /

Swift requires the operands in all arithmetic operations to be of the same type.

Consider the following statements:

var a = 9 //Int
var b = 4.1 //Double

By using type inference, a is Int and b is Double.

Because they are of different types, the following operations are not allowed:

print(a * b) //error
print(a / b) //error
print(a + b) //error
print(a - b) //error

You need to convert the variables to be of the same type before you can perform arithmetic operations on them.

## Related Topics

## Exercise