Geoboards are fun tools to teach your child the basic concepts of shapes and how they work in math; any kid would love a gigantic one! Firstly, you need to obtain a pegboard (what they hang merchandise on in hardware and similar stores). They usually come in 4x8' sheets, so you may need to ask an employee to cut one into fourths for you. The fourth piece should have 64 holes in 8 rows of 8, which means you need 64 nuts and bolts to make the board. Assembly is a no-brainer; you and your kids screw in the nuts and bolts, then tighten them with a wrench. Then grab some colored rubber bands, easily attainable via rubber band balls (can be found in office supply stores or warehouse stores like Wal-Mart) and start making shapes!