auto-adjust cell size

Hello,

I've noticed over the years that Excel will sometimes auto-adjust cell/column width when a numerical entry is too large to fit, but other times it just displays #####. Why doesn't it behave the same all the time, and is there a setting I've overlooked that can control the behavior so it consistently auto-adjusts the cell when the entry is too large to fit?

P.S. I wouldn't want text cells to auto-adjust, only cells with numerical values.