Preparing the zero state and counting readout decisions turns calibration into a finite row ledger. The row fractions are exact only for the stated prepared state and counts; real hardware adds preparation error, threshold drift, detector noise, leakage, crosstalk, and finite-shot uncertainty.
Calibration begins by preparing a known zero state and counting readout decisions. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Prepared zero gives calibration counts
When zero is prepared, the readout counts are 9 zero decisions and 1 one decision.
Nread zero=9,Nread one=1
Counts become a probability row
The row is 9/10 and 1/10, because the total is 10.