Visualizing 'Between-ness' in Addition and Subtraction

① This GeoGebra example dynamically demonstrates how the result of addition (a+b) and subtraction (a-b) lies 'between' the two operands on a number line, using random numbers and interactive bar charts. ② Core mathematical concepts include addition, subtraction, linear relationships, symmetry, geometric mean, and an introduction to linear regression for observing data trends. ③ Construction highlights: The Random command generates random values for a and b, while Max and Min determine bounds; buttons (button1, button2) trigger random refreshes; objects such as points T1, B1, T2, B2 and segments c, d, e, f represent intervals; text objects dynamically display results and the 'between' relationship; sliders or buttons enable interactive exploration. ④ This resource is suitable for upper elementary to middle school students learning properties of operations, and for teachers demonstrating number sense and inequality intuition, laying groundwork for linear equations and regression analysis.