The purpose of this material is to introduce the child to the unit combinations of subtraction. Includes: 1 box containing 5 sets of Negative Bead Stairs, 1 box containing 5 sets of Colored Bead Stairs, 1 box containing 23 Golden Bars Of 10, and 1 box containing 1 Black And White Bead Stair. The 4 boxes fit neatly into a beechwood tray.