Calculating change from cash register

Question

I'm making a cash register system with OO and I want to make it modular so you can add different currencies.

So I have this enum to store the currencies:

class Currency {
enum PoundSterlingCurrency {
    Fifty_Pounds(50f),
    Twenty_Pounds(20f),
    Ten_Pounds(10f),
    Five_Pounds(5f),
    Two_Pounds(2f),
    One_Pound(1f),
    Fifty_Pence(0.5f),
    Twenty_Pence(0.20f),
    Ten_Pence(0.10f),
    Five_Pence(0.05f),
    Two_Pence(0.02f),
    One_Pence(0.001f),

    private final float value;
    private final String description;

    PoundSterlingCurrency(float value) {
        this.value = value;
        this.description = this.name().replace("_", " ");
    }

    public float getValue() {
        return this.value;
    }

    @Override
    public String toString() {
        return this.description;
    }
}
//Add more currencies here

}

My getChange method

public void getChange(double cash, Product product) {
    double cashBack = cash - product.getPrice();
    if (currency == Currency.POUNDSTERLING) {
        for (PoundSterlingCurrency c : PoundSterlingCurrency.values()) {
            while (cashBack >= c.getValue()) {
                System.out.println(cashBack);
                cashBack -= c.getValue();
            }
        }
    }
}

With the print statement that I have when i calculate the change, I get the following

41.25
21.25
1.25
0.25
0.04999999999999999
0.02999999999999999

In this example, the product has a price of £8.75 and there's £50 that's used to buy it. Therefore, I need to calculate the change.

This shows that when I minus 10 pence away from 25 pence when calculating the change, I somehow get 0.04999...

I could just round the answer each time to check, but surely this isn't good practice if I don't know how this occurs.