All graded pass test although 50/100 grade

First programming assignment completed with all graded tests passed and after submission only 50/100 grade received.
I haven’t done non-graded section.

This is a very common issue.

The unit tests don’t catch every possible error in your notebook.

In particular, it doesn’t verify that you applied the ‘stride’ variable correctly.

To see if the error that Tom points out is active in your case, look very carefully at the results you get from the stride = 2 test case for pool_forward. All the numbers need to agree, not just “most” of them. But there is a bug that the test case does not throw an error if your values don’t match in that case.