The guppy in the pet store ripples through the water as he swims, so Carlos names him Ripley. Carlos wants to buy Ripley, though first he needs to set up a fish bowl at home with a little help from big sister Ana. He pours a cup of water into the bowl, but it isn't nearly enough. Then another cup, which makes a pint. But he needs more. How many pints make a quart? How many quarts in a half-gallon? In a gallon? It sure takes a lot of water to keep a little fish happy!

Children need to understand the relationships between the various units used to measure liquid capacity.

MathStart is an award-winning series by Stuart J. Murphy that teaches math through stories and visual models. Young readers find the stories engaging and relatable, because each story revolves around practical applications of the math concept being presented and features lively art from top-notch illustrators.

Charts and other visual representations help children understand how the math works and promote deeper comprehension. This unique combination of stories, illustrations, and visual models helps teachers and parents in the teaching of math and provides all children with the opportunity to succeed.

The 63-book series is divided into three levels with 21 books in each. The math concepts taught in MathStart books conform to state and national standards. Level 1 is Pre-K–Kindergarten; Level 2 is Grades 1–3; Level 3 is Grades 2–4. The series follows math topics across grades so there is a foundational path to learning that runs through the levels.