This happened just three days ago, during instrument training, while copying and reading back a clearance for only the second time ever.
Clearance Delivery (after I'd read back my clearance correctly) :
"Readback correct. What runway, and how long?"
"Runway 03, and it's 4,200 feet long."
I can only imagine what the controller said at that time. My instructor keyed in immediately to clear things up.
Ed. Note: We've had more than our usual share of chuckles from "Short Final" entries these last couple of weeks, but it's rare that pilots even student pilots 'fess up to being the culprits in the telling.