If you do have to pause and think every time you are confronted with 5 times 7, you are burdening your working memory with that task and taking up valuable space. As Willingham put it, “It is no wonder that students who have memorized math facts do better in all sorts of math tasks than students whose knowledge of math facts is absent or uncertain. And it's been shown that practicing math facts helps low-achieving students do better on more advanced mathematics” (Willingham 2014, p. 114).
