Refresh my memory please, dealing with multiple '='

[SMcNeill]

@George McGinn -- limitations of variable types.  Floating point numbers have a representation for NAN; Integers don't. 

In 32-bit floats, NAN is stored as: 0x7fc00000.

First bit is 0 for sign.
Next 8 bits are set for a value of 255.  (Special)
Mantissa is 1 with all zeroes...

Which represents NAN.

Integers don't have such an encoding built into them, thus integer division doesn't return it as a result.

https://gregstoll.com/~gregstoll/floattohex/