We examined the math facts fluency growth of students receiving explicit timing practice in either a massed, short-distributed, or long-distributed fashion. In a repeated-measures group design, 50 mid-western 3rd grade students completed four one-minute math probes each day for 20 days. Hierarchical linear modeling revealed that students who received practice separated by a three-hour interval grew significantly more than students who practiced with a ten-minute distribution or a massed presentation.