Counting-on with finger patterns was procedurally efficient enough to be used in instruction in multidigit addition problems; second graders successfully learned to use counting-on with finger ...

Karen C. Fuson, Adrienne M. Fuson, Instruction Supporting Children's Counting on for Addition and Counting up for Subtraction, Journal for Research in Mathematics Education, Vol. 23, No. 1 (Jan., 1992 ...

Here's why math fact fluency matters, and what we know from research about teaching strategies and timed exercises.