Because CMU CS Academy uses a specific 400x400 canvas grid, calculating the exact boundary box for an interactive element requires precise math. Missing a boundary by even one pixel will cause the exercise's test cases to fail. Step-by-Step Guide to Solving 6.3.5

Many students struggle with the variation of 6.3.5, where an icon must "bounce" off the walls.

In this lesson, you are tasked with moving a Group or shape continuously using the onStep function. 1. Initialize Movement Variables

Unit 6 is a turning point in the CMU CS Academy curriculum. It shifts from static drawings to . Mastering 6.3.5 proves you can handle multiple variables changing at once—a fundamental skill for game development and advanced simulation.

Using dx and dy properties to control the speed and direction of objects.

The foundation of the exercise is importing data. Instead of manually typing lists like data = [10, 20, 30] , students learn to read from a file. The typical pattern involves: