Another cool approach to this problem is to reflect either the hole or the ball over one of the sides and see if there is a direct line shot. Stripping down problems from all the textbook chatter is a grand way to get students thinking. And students defining their own problems is brilliant!
A potentially fun PEMDAS BINGO game.
NOTE 1: The provided problems all use 3-5 integers, basic 4 operations, & parentheses.
NOTE 2: Very few parentheses and no exponents, roots, or absolute values are used.
NOTE 3: This can easily be strengthened with other expressions, if needed.
This is a really cool approach to student learning & self-assessment. Jill uses a calculus example to make her point, but it could easily be applied to almost any other math (or other discipline's) content.
It is a pretty radical departure from where we currently are, though.
This is a lovely fractions problem. I suspect most would try to find common denominators as that is what they've been trained to do. In this case, common numerators are easy to find and make the solution easier.
Thinking of areas as a way to compute products leads to some lovely division possibilities in later algebra courses. Jim Tanton's "Galley Method" makes this particularly elegant.
Here's a different posing of the problem:
This figure is a rectangle sub-divided into 10 different-sized squares, each with a different integer (counting number) side length.
What are the dimensions of the rectangle?
Is the rectangle really a square?
How many solutions are there? How do you know?