The document discusses metrics, dimensional analysis, and examples of unit conversions. It introduces the metric system which uses base SI units and prefixes that are multiples of ten. Dimensional analysis allows simple unit conversions by identifying conversion factors that relate different units and cancelling units to isolate the desired unit. Examples provided include converting between feet to inches, inches to feet, days to hours, minutes to seconds, centimeters to meters, meters per second to hours, and miles per hour to feet per second.