YOUR TAX-DEDUCTIBLE CONTRIBUTION PURCHASES THIS ITEM FOR OCS - THANK YOU! The kit offers students a place to write a problem (up to three digits) on the write on/wipe off mat, and the sturdy manipulative pieces help them solve the problem right on the mat. The mats and chips are color-coordinated and perfect for small group work, independent practice, or learning centers. The kit includes four mats and 216 thick cardboard manipulative chips (72 each of ones, tens, and hundreds).