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Learn Java: Manipulating Variables

Multiplication and Division

Let’s say that our employer is calculating our paycheck and depositing it to our bank account. We worked 40 hours last week, at a rate of 15.50 an hour. Java can calculate this with the multiplication operator `*`

:

```
double paycheckAmount = 40 * 15.50;
//paycheckAmount now holds 620.0
```

If we want to see how many hours our total balance represents, we use the division operator `/`

:

```
double balance = 20010.5;
double hourlyRate = 15.5;
double hoursWorked = balance / hourlyRate;
//hoursWorked now holds 1291.0
```

Division has different results with integers. The `/`

operator does *integer division*, which means that any remainder is lost.

```
int evenlyDivided = 10 / 5;
//evenlyDivided holds 2, because 10 divided by 5 is 2
int unevenlyDivided = 10 / 4;
//unevenlyDivided holds 2, because 10 divided by 4 is 2.5
```

`evenlyDivided`

stores what you expect, but `unevenlyDivided`

holds `2`

because `int`

s cannot store decimals!

Java removes the 0.5 to fit the result into an `int`

type!

In `main()`

, there is a variable called `subtotal`

, which represents the subtotal of an amount to pay on a bill, and a variable called `tax`

, which represents the amount of tax added to the subtotal.

Create a `double`

variable, `total`

, that holds `subtotal`

plus the product of `subtotal`

and `tax`

.

Print the `total`

variable!

There were 4 people who bought this meal together and want to split the cost.

Create a `double`

variable called `perPerson`

that holds `total`

divided by 4.

Print the `perPerson`

variable!