This genre of problems is a goldmine. Simple, gorgeous shapes. Area. The meaning of fractions. Operations with fractions. Visualization. Breaking shapes into simpler ones. Multiple paths to solutions. Connections to repeating decimals. Chances for students to create problems.
Kids love to share what they see in these diagrams. There are so many “aha” moments. Kids are so proud when they “see” it and feel suddenly very empowered—problems that seemed completely intractable a moment ago are suddenly so transparent.
Here’s a sheet to get you started. I have a fair number of these problems that I’ve made (in Cinderella, mostly), and they’re kind of sequenced, but also somewhat pell-mell. I would probably organize and share them if given a nudge. (: