We use Scott-Addison Wesley Math Curriculum.
In addition to the math curriculum, students in these grades are required to memorize their multiplication tables from 0-10 (if in third grade) and from 0-12 (if in fourth grade). A fun way we memorize these sets is through a fun multiplication workbook. Also, I utilize weekly math quizzes. Starting in the middle of September, students will be quizzed weekly, starting at the easiest: 0. If they pass, the next week, they get to tackle the next set. Each set that they pass earns them an item to complete a full ice cream sundae. We call this, "Pig Math," as they are earning the right to "pig out" on an ice cream sundae. The ice cream party usually happens in the Spring.