Metric Rod Series are effective tools for physically representing various math concepts. Not only do they demonstrate numerical, place and equivalent values; but also teach simple math calculations. With hands-on practice, the child can learn the relationship between units, tens, hundreds and thousands. As each unit is 1 cm on all sides, children can also practice measuring and calculating length, area and volume. - Marked Metric Rod Set and Series contain weights that are equivalent to the length, and can be used as weights with a balance. The markings on the rod also allow the child to visualize many math concepts more easily. - Plain Metric Rod Set lunweighted) strengthens the child's observational skills by allowing the child to practice ruler measurement and visual estimation.