I use this in my Harry Potter 5th Grade Math Unit
at the end of the year as a review. However, it can be used as a stand alone lesson for Adding and Subtracting with Fractions of unlike denominators and Converting Metric Units of Capacity.
You do need additional materials for this lesson (list included in materials) to create the "potions"
Common Core 5th Grade Math Standards Covered:
Add and subtract fractions with unlike denominators (including mixed numbers)
Convert among different-sized standard measurement units within a given measurement system (e.g., convert 5 cm to 0.05 m)
Add, subtract, multiply, and divide decimals to hundredths