Volume: English 1

Volume takes the stage here, with 10 questions that break gallons down into quarts and then into pints.

A line such as 1.25 gallons or 0.50 gallons asks for the answer in quarts or pints, so you practice the customary liquid units used on US drink and fuel labels.

The stacking is the tricky bit: a gallon splits into four quarts, and each quart splits again into two pints, which means a gallon hides eight pints inside it. Once that nesting clicks, juggling these units gets a lot less confusing.

Recommended level: beginner to intermediate.