Photon count drives packet energy across a fixed budget. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Photon packet energy is counted against a budget
The toy photon energy is fixed; only the packet count changes.
m=Emax−Epacket
Three packet counts bracket the energy budget
The middle row uses the whole budget. The final row exceeds it.
N123Epacket61218m60−6gatepasspassfail
The three-photon packet is over budget
The helper computes the total energy first; the lesson gate only compares it with the budget.