Use every card exactly once to make the target. Pick a card, pick an operation, pick another card: they combine into a new card, and the work shows how the common denominator was found.
The goal. Combine all the cards into one card that equals the target. Every deal can be solved; many have more than one solution.
A move. Tap a card, tap +, −, × or ÷, then tap a second card. The two cards are replaced by their result, written in lowest terms. Dealt cards are not always in lowest terms (4/6, 6/10), which is part of the practice. Undo takes back one move.
Adding and subtracting. The work panel rewrites both fractions over their least common denominator before adding: 2/3 + 3/4 = 8/12 + 9/12 = 17/12. Watch for when the answer reduces.
Levels. Level 1 uses one denominator. Level 2 uses denominators where one divides another, such as 4 and 8, or 3 and 6. Level 3 mixes unrelated denominators with four cards. Level 4 adds × and ÷, like the classic game of 24.
Hints. A hint shows one move that still leads to the target from where you are. Using a hint keeps your streak but is counted.
Play on paper too. The same game works with index cards: deal three or four fraction cards and a target card, and the first person to say a correct expression takes the round.