They create and play board games that are played on horizontal tracks with the negative spaces to the left and positive to the right. Students develop their own addition and subtraction strategies and use estimation and multiple strategies to double-check their work. Students compare their own data, such as the number of children in their family or the ages of their pets, with world record data. They use pan balances to compare the weight of cut-up pieces of fruits and vegetables before and after one or two days exposure to air. Students also solve problems involving comparisons on the calendar, for example, figuring out the number of days until a particular event and determining how much longer children in other countries spend in school than they do.
Students explore problems involving paths, lengths of paths, perimeter, and turns.
Students create paths on the floor, on paper mazes, and on the computer using Geo-Logo . They write commands, such as forward 5, left turn 90, forward 2, to provide directions for other students or for the computer turtle to move along these paths. Students define triangles and draw them with the Geo-Logo turtle. The unit ends with each student writing procedures to design a face on the computer. Students sort, build, and describe different kinds of polygons and common geometric solids.