Using the Durability Display to Manage Mending Repairs
Mending repairs items using experience, and the mod's display makes it much easier to see whether an item is actually healing or still losing durability.
Reading the Number Correctly
When an item is close to full, the mod shows the amount of damage the item has taken rather than the remaining durability. That means a small number next to a nearly full tool is good news: it is the damage value, and you want it to shrink toward zero. Once the item is more worn, the display switches to showing remaining durability, which counts down toward breaking. Learn which mode you are seeing before you panic about a number.
Repairing Efficiently
Wear the item down, then collect experience while holding it or wearing it so Mending can apply. Watch the number change as you pick up orbs: if it is showing damage, the value should drop; if it is showing durability, it should rise. If nothing changes, the item may be at full durability already or Mending is not on that piece. Use this feedback to decide when to stop grinding mobs and move on, and to confirm Mending is working after enchanting or trading for it.