See how a running total differs from a rate of change using parcel deliveries:...

https://activecalculus.org/author/Running-Totals-Rates-of-Change

See how a running total differs from a rate of change using parcel deliveries: 120 parcels by noon is a total, while 15 parcels per hour describes a pace. The article shows how units and time windows make dashboard numbers easier to interpret.