Conversation so far:
where is the mass air flow sensor located
The mass air flow sensor may be located in a different position down the intake plenum just after the air box but will always be before the throttle body.
what does the mass air flow sensor measure
the mass air flow sensor measures the amount of air entering the engine

Question: what can be calculated from the measurement
Self-contained rewrite: what can be calculated from the mass air flow sensor measuring the amount of air entering the engine