#3 Division by Zero

[leam hall]

I entered only some values into the fields that were showing bold labels. I assumed the other ones are optional and not needed. In any case, doing that generated several devisions by zero => all input is evil, that includes no input at all (I used 100, 2, 3, 4, 5, 6, 7 from top to bottom)
Here are the two division by zero errors:
Warning: Division by zero in /home/gershom/public_html/dive/dive_class.php on line 33
Warning: Division by zero in /home/gershom/public_html/dive/dive_class.php on line 40

Those didn't go away when I entered something into every field.

[leam hall]

The original division by zero issues are fixed. However, there's a larger ticket for unit testing and one for input validation.