Multiplication as a mapping between number lines

Multiplication as a mapping between two number lines

k = 1.00
Input number line (x) Output number line (kx) x ↦ kx
Slide k from +1 towards 0 to see all outputs contract towards 0. Continue into negative k to see the mapping reverse direction, producing sign flips. When outputs exceed the displayed range, lines are clipped at the plot boundary with an arrow to indicate continuation.