Blender is changing my transform values

I’m following a tutorial online that has me entering exact values into the dimension, extrude and grab methods. i.e. 16, 31.5, 32, etc. However, I’m noticing that when I select edges after the fact - almost always it’s the Y median in the transform section - it’s not the exact value that I entered. It’s off by some small decimal. Why does this happen? I’m worried that if I were to create a large structural environment that required precision that the small errors would add up over time. Also, as I’m going through and selecting edges to check if they are offset by that small decimal, it seems as though there are multiple edges in the same place. How could this have happened? And how can I remove the redundant edges?

Not 100% sure what’s going on there but median value is the center point between selected vertices/edges/faces. That can change when one or more elements change place but the others don’t follow the same amount.
For example, an edge that has its center at point 2 - it will be 2 if you just scale it along its length, but changes if you move the other end only.

Also, when you post in the future, here are some suggestions to get your questions answered quickly:

  • You’re following a tutorial, give a link to it. Tell what parts are important to your question, where it goes wrong. If possible, direct links to written tutorial sections, or video links with time tag so that the reader doesn’t have to go through a long tutorial just to help you. Most won’t.

  • Visuals are important. It’s hard to imagine things and take guesses what could be wrong, or what the goal is. Since you’re new, you might not be able to attach a .blend file just yet. In that case, you can use pasteall to upload your images or .blend and then link to them here.

  • If you take screenshots, only personal information is what no one needs to see and you should take those parts out. Everything else is bit of information you want to give out. Don’t cut it, don’t scale it so that it’s hard to see, don’t close the sections in the panels.

  • Use paragraphs.

Thanks. I will keep that in mind when posting in the future.

I think I got to the bottom of the random decimal values:
#1: The initial plane I began with wasn’t exactly at the center. So every extrusion had a similar offset.
#2: I wasn’t consistently using the axes to guide the extrusion. So every extrusion went off on a slight angle from my reference, causing the end result to be off by a slight decimal.

After starting over from scratch and being more meticulous with my technique, I found it’s completely possible to have perfect measurements if necessary.