Complete Beginner. How can I round decimals to .5 system wide?

Hey everyone, I am new to home assistant and have been having fun setting up my dashboard. The community is a ton of help! I’m looking to have all my temp/humidity etc values rounded to the nearest .5. It looks a little silly when my tablet says the indoor temp is 21.8C directly next to my nest that says its 22C. Can someone explain in the most beginner friendly way how I go about doing this? I would really appreciate the help!

There is no global setting. It has to be done on a sensor by sensor basis.

Ok, thank you! At least I’m not chasing something that isn’t possible now.