As the parent of a gifted learner you may wish to expose your child to more advanced mathematics without pre-teaching material they'll be exposed to in school in due course. Ed Zaccaro's math books answer the call for material that truly and appropriately challenges mathematically gifted children. Use these titles to expand your child's understanding without simply accelerating them in a standard curriculum.
For the child who is gifted in mathematics their reward is often more of the same with perhaps a few more difficult problems added to the mix to keep them occupied. Math is often taught as all scales and no music. These books add the music. Children will be shown the fascinating connections between mathematics and the real world and be taught that challenge and frustration are part of learning and life. They'll learn to appreciate their gift for mathematics as they advance their skills.
The type of problem solving and thinking around the problem that these math books teach is what is needed to do well in many tests for gifted program entry where quantitative reasoning is tested.