Math fluency standards, defined as accuracy and speed, continue in grade 1 with additional facts. Students should be able to add and subtract within tens. (ie 10 + 10 = 20 and 20 - 10 = 10). Memorizing basic facts is essential to math success! As concepts and skills increase over time, the short term memory needs its power to for conceptual practice of new skill. If all the brain power is spend on recalling basic facts, it cannot complete complex tasks. It is that simple!