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

https://storyquanta.com/s/eroIh5770ECD5iCO7W72u

See how a running total differs from a rate of change with parcel deliveries: 120 parcels by noon is a total, while 30 parcels per hour is a pace over a time window. Clear units help you read the chart and explain what changed.