I'm trying to calculate a percentage "factor". That is, given a 20%, convert it into 0.2 (my intention is to later multiply values by that and get the 20% of the values).

Anyway, the question is related with this piece of code:

```
public static void main(String[] args) {
int roundingMode = BigDecimal.ROUND_FLOOR;
BigDecimal hundred = new BigDecimal("100");
BigDecimal percentageFactor = null;
BigDecimal percentage = new BigDecimal("20");
BigDecimal value = new BigDecimal("500");
percentageFactor = percentage.divide(hundred, roundingMode);
float f = percentage.floatValue() / hundred.floatValue();
f = value.floatValue() * f;
BigDecimal aux = value.multiply(percentageFactor);
System.out.println("factor:"+percentageFactor.toString());
System.out.println("final falue:"+aux.toString());
System.out.println("Float Value:"+f);
}
```

I would expect the outcome of this to be something like:

```
factor: 0.2
final value: 100
float value: 100
```

but instead `percentage.divide(hundred, roundingMode);`

is returning zero, an hence I get:

```
factor:0
final falue:0
Float Value:100.0
```

What am I doing wrong? How can I divide two big decimals properly?

By the way, I'm using `BigDecimal`

because I will be calculating monetary percentages, so I want control regarding rounding.

## Best Answer

I think that the best solution is to set the requested scale when dividing: In this case perhaps 2.

Final value:

`100.00`

The multiplication is using the scale from the factors (0+2) but it can be specified too.

I'd use

`ROUND_HALF_UP`

for accounting (in my legislation) or`ROUND_EVEN`

(for statistics) for rounding mode.