Math facts response

In RB we too give time tests for basic facts. We test addition, subtraction, multiplication, and for some students, division. I test addition for first quarter. I test subtraction for second quarter. I test multiplication through the nines for third and fourth quarter. If they finish the times facts, they go onto division. We do 40 problems in two minutes for multiplication. For subtraction and addition, I either do 40 problems in two minutes or 100 problems in five minutes. Even though I test addition and subtraction once a week during first semester and mult. and div. three times per week second semester, teachers in the upper grades still complain they don't know their facts. Mona