Number transformations in Power Query are simple to do, but there is something you need to watch out for when you have null in one of your columns.

Let’s consider a simple example where we have employees listed with their annual salaries and their end-of-year bonus. Not everyone got a bonus, so you will see null in a few cells of the bonus column. In the original Excel table, there was nothing in those cells where the bonus was zero.

Below is the screenshot of inside the Power Query Editor. Notice that we have a problem.

We’ll use List.Sum() instead of the plus sign. Now we have the correct numbers.