A reported bin is honest only when its low and high endpoints are explicit. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
A narrow bin has close endpoints
Center 12 with resolution 2 gives interval 11 through 13.
12±1⇒[11,13]
Doubling resolution widens both sides
resolution 4 gives interval 10 through 14. The center stays fixed while the endpoints move.
12±2⇒[10,14]
A wider bin must show its larger uncertainty
resolution 6 gives interval 9 through 15. The scan makes endpoint growth explicit.