Lakeshore Hands-On Math Trays - Complete Set Description Children sort, count, pattern, graph and compare—with large skill-building trays that are perfect for use with our Math Counters! Children just place the counters right into the trays to explore concepts hands on…and easily keep the pieces in place as they work! Complete set includes all 5 sturdy plastic trays shown(math counters not included); trays measures 10 3/4" x 14 1/4".