Multiplying Integers on a Number Line: Visualizing Sign Rules

This GeoGebra applet uses a number line to visually demonstrate how integer multiplication follows the sign rules: like signs give a positive product, unlike signs give a negative product, and multiplying by zero yields zero. It focuses on the relationship between integers and their graphical representation on a number line, turning the idea of “multiplication as repeated grouping/scale” into directed movements or corresponding positions. The construction relies on GeoGebra commands Arc (to draw arc-based direction or auxiliary cues), If (to branch the display based on whether operands are positive or negative), and Sequence (to generate ordered values that drive the positions/steps of the visualization). Key objects include several points (A, B, a, b, c, d), lists for storing computed data (lista1, lista3), and multiple text labels (texto1–texto4) to present the rule and the computed outcomes. Best suited for middle-school students learning integer arithmetic, classroom demonstrations, and interactive practice on sign conventions in multiplication.