This great tool helps you quickly build a hundred chart on your whiteboard…then build on easily to teach up to 120! Special t-shaped piece is an effective new tool in popular math programs that help build mental math fluency. Dry-erase surface allows for easy circling and easy clean-up. Includes chart pieces, 0 piece, 20 highlighting frames, 20 cover-up squares, and unique t-shaped more/less piece. Assembled chart measures 24"W x 34"H.