The major emphasis in all Unified Sciences and Mathematics for Elementary Schools (USMES) units is on open-ended, long-range investigations of real problems. Since children often design and build things in USMES, 26 "Design Lab" cards provide information on the safe use and simple maintenance of tools. Each card has a large photograph of the tool or tools on the top. The first frame on most cards is a photograph of a child holding the tool, providing the user with an understanding of how the tool is held. Remaining frames describe important skills in using the tool. Primary grade students or older students with reading problems should find the large photographs/illustrations useful in understanding the material presented with little reliance on accompanying word descriptions. Tools described include: electric tools (saber saw, electric drill, glue gun, soldering gun); handsaws (crosscut, coping, keyhole saws and hacksaw); other hand tools that cut (files, circle cutter, wood chisel, block plane, hand drill); holding tools (pliers, "C" clamp, screwdriver, hammer, size of nails); and measuring tools (combination square, rafter square, level). Additional cards provide instructions for maintaining a saber saw and electric drill and for making a sawhorse, tri-wall slot, and bend in a tri-wall. (Author/JN)