Bring word problems to life (and make them concrete!) with clam shells and fun little crab and sea-star counters! Perfect way to practice addition, subtraction, and finding the missing number. Includes 40 double-sided word problem cards (80 word problems), 4 clam shells, and 80 counters (40 crabs and 40 sea stars both in 2 colors). Clams measure 12cmL x 10cmW x 3.8cmH.