Numbers, BigInt, and Numeric Operations

#Most JavaScript bugs that look mysterious at first are ordinary value, conversion, or binding mistakes. The useful skill is learning exactly what value a variable holds at each step. In this lesson, the practical target is numbers, bigint, and numeric operations: you should be able to predict what the runtime will do before changing the code.#link

This example demonstrates numbers, bigint, and numeric operations directly. Change one input at a time and observe the result; the goal is to connect the syntax to the runtime behavior rather than treating the snippet as a recipe.

A common failure with numbers, bigint, and numeric operations is changing several variables at once. That hides which rule actually caused the result.