Have you tried Andrew Stadel's Stacking Cups Lesson? If not, it is a great way to model linear equations as well as using a system of equations to find a solution. The problem asks students to find how many cups will be needed until the stacks of cups are the same height.

This coding task was inspired by Andrew Stadel's Stacking Cups Lesson.
Students will model two different types of cups being stacked based on their heights. They will use the model to find when the two cups will reach the same height.