A finite converter range is divided into exact code steps. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
The converter has a finite voltage range
The ideal range starts at 0 volts and ends at 8 volts.
[0,8)V
Eight codes divide the eight-volt span
The 8 volt span divided by 8 codes gives a 1 volt LSB.