DON'T SHOUT SO LOUD!
I have delicate ears you know...

I think you are referring to your course notes here.
I hope you can read your own language : Habla espagnol?

I googled with bit operations in C the first hit I got was
...

THe best tutorial I can think of is your course notes and your textbook. Or are you missing both?
At least show us what you already have. Please?

You do not need to free local variables when the function ends. Where would they be anyway? Who or what could still access them?

The thing is that enum in C are a sort of integer constants.
So you could also use #define Sunday 0 to accomplish the same thing. You could let the user input a number or character and then add a...

Comment out the scanf for the moment.

Try
today = Sunday; or today = Friday;

An enum under the hood is stored by most compilers as an integer so the name Sunday is really a placeholder for the integer value 0. Monay evaluates to 1, Tuesday to 2 and so on.
You are giving the...

You want to print a table with the powers of 2 and you want your integers to be signed and unsigned. You're making it to complicated I think, use \t to separate your output. Or use something like...

No harm done:)

Well I shall do the reverse:
Take 101
Instead of divide, multiply by 2 for every "remainder":
1 x 2^0 = 1
0 x 2^1 = 0
1 x 2^2 = 4

1+0+4=5 decimal which is 101 binary.

I don't know what your problem is, but I appreciate your efforts.
Divide your decimal number by 2. Record the remainder(should be 0 or 1) divide again and record again until your decimal number...

OK use a post-test loop. Where in your question is mentioned that you may not use for, if, break or whatever at the same time?

The trills you get when some code is working can not be described by someone who has never written some code...
Mark thisone as solved...

Code tags :
Select your code.
Then click one of the buttons on top of the field where your typing or pasting text.
Hover over all of them to get their meaning. You need the #-button.

Code...

Why do you make it so complicated?
You can do with one while!
And please : if you send code put it between CODE-tags

main()
{
int num, i;

while(num>1) <-----
{

What do you think the value of num is where I put the arrow?
Most likely it will be zero but you can never be certain about that.
Put your scanf...

Could it be that your return statement in the sum-function is in the for-loop?
It is indented that way.

set choice to 3 before the while-loop
do the scanf in the
while loop
1--func 1
2--func 2
3--quit the while loop , do something like while (choice != 3) etc.

In your while loop, you never change the choice variable to something else then 1.
It is testing for choice==1 or choice==2 so it will keep looping forever.