1.I didn't finish the work a hundred percent.

2. I didn't finished the work completely.

3. I finished the work in part.

4. I didn't finished the work at all.
--------------------
Are #1, #2 and #3 the same?#4 is not the same, right?

2 answers

I cannot find the example sentences with the structure
"not ...a hundred percent" on the Internet.
There will not be examples of "not...a hundred percent" because it's not normal phrasing.

"I didn't finish the work" is all you need.

2 and 3 are OK -- meaning I did part of the work, but didn't finish.

4 will be OK if you use "finish" instead of "finished."