Answer:

Analysis of extended data types;

One-way 20 kilometers, round-trip is limited to formation round-trip, round-trip 40 kilometers. Round trip five times a day, that is, five 40 kilometers, which needs multiplication.

A shortcut to add up the same numbers. The result of its operation is called product, and "X" is the symbol of multiplication. From the philosophical point of view, multiplication is the result of qualitative change caused by additive quantity. The multiplication of integers (including negative numbers), rational numbers (fractions) and real numbers is a systematic summary of this basic definition.