Proportion, slope, ratio, angle, cross multiplication.
App that attempts to graphically show what is routinely done with cross multiplication.
It focuses on graphically showing the idea of proportion, and the equivalent fractions for solving directly proportional problems.
Shows the slope, the ratio, the proportion between two numbers, and allows applying that proportion to other numbers, whether they are greater or less than the initial one.
Graphically the proportion is fixed with the red bars.
The blue dot slides down the slope fixed by the proportion