I'm not sure I understand the question.
What exactly do you mean by division expression?
I will answer the question the way I understand it.
a / b = c ( in real numbers )
a/ b =/ c (=/ is not equal) ( in integer arithmetic )
lets sub some numbers in and you can see better.
a = 12.3, b = 5.0
Then the first equation is
12.3/5.0 = 2.46 (for real numbers this is ok)
The second equation is
12.3/5 = 2 ( for integer arithmetic )
so the first equation and second equation are not equal.
One more way division can have several answers.
Lets look at 1.0/3.0 ( real numbers ) ... If you type that in you know the answer is just
0.333333333333333 ----> it goes on forever but saying 0.33333 is equal to the original statement.
0.333333 = 1/3 .... is false because they are different. One is an approximate answer and one is exact.
Similar arguments can be made for e and pi ... they are exact values so any type of decimal answer is approximated and therefore different.
Hope this helps. Let me know if you have any other questions.