I'm trying to calculate the amount of days between two dates (note: one of them is in datetime format, and the other is date)

Later I'm using a formula tool to classify everything that is below 44.50, but I'm having the following issue;
It seems like .50 is not being considered in my formula tool. No matter if I have 44.51 or 44.49 alteryx will say it is 44.
Decimals are important to me in this situation. I need to filter out everything that has less than 44.49 days. 44.50 an above should be kept.
I have tried to change the format in the screenshot above to fixed decimals, but it didn't work out either. Any thoughts on how I can troubleshoot this?
Second issue I'm having is that if I remove the tonumber from the screenshot above alteryx returns the following error:
