Illustrated Commentary on the Nine Chapters on the Mathematical Art, Volume 1

As follows

A diagram depicts a rectangular grid divided into 12 columns and 14 rows, representing a field. The right side is labeled "Length 14 steps." The bottom side is labeled "Width 12 steps."

Field Measurement

The Rule states: Multiply the number of steps of the width and length to obtain the square steps. This product is called the field power mi area/power. Any multiplication of width and length is called a power.

I, Chunfeng, and the others, respectfully observe that the Classic states: "Multiply the width and length to obtain the square steps." The commentary says: "Multiplying width and length is called a power." Observing this commentary, the meaning of "product" and "power" is the same. Reasoning from principle, this is certainly not the case. Why? The "power" mi is the name for the flat surface of a shape. The "product" ji is the name for the aggregation of multiple numbers. Following the name to demand the reality, the two are completely different. Although one may wish to equate them, I fear...