The source packet is an exact energy ledger, not a reaction model. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Packet bookkeeping is not reaction kinetics
This model stores only packet count 5 and packet energy 12 joules.
5packets at12J
The honest claim is the total
The only output of the packet ledger is input energy 60 joules.