Program that requests two floating-point numbers and prints the value of their difference divided by their product
For a newbie, your solution is ok. You can simplify it quite a bit though by using the function fabs. It's a fairly simple function: fabs(x) returns x if x &gt;= 0, and returns -x if x &lt; 0. So all of your if checks can be replaced by the line:

different = fabs(num1 - num2);


Note that you need to #include &lt;math.h&gt; for this.

Also, what happens if one of your numbers is 0? Then your product will also be 0 and your program will crash. It's always a good idea to add some basic checks. Unfortunately, with floating point numbers this can be a bit tricky, so simply doing something like:

if(product == 0.0) { ... }


may not actually work! Fixing this might be a bit tricky for someone who is just learning, but it's something to always keep in mind.

Finally, main should return an int - generally, 0 is what is returned if everything works as it should - so down the bottom should be a return 0;.