This Practice prompts the user for a number twice, parsing the response into number values.
A conditional statement then checks if:
1. the second user input is a zero, and if
2. either of the user inputs is not a number.
If either condition is true, an appropriate warning is alerted
If both conditions are false, the numbers are then placed into a message that is printed to the screen with calculations for the add, multiply, divide and subtract methods
View Page Source for examples of the code used.