Two-Minute Math Drills, Grades 1 – 3 [PDF ebook] 
Addition & Subtraction

The Two-Minute Math Drill Series helps students gain proficiency in working with math facts. This book focuses on addition and subtraction and offers 55 reproducible practice pages with 30 problems in each page. The problems represent a wide range of difficulty; from single-digit to double-digit sums and minuends, with and without regrouping; so students of various levels are appropriately engaged. The two-minute time limit for each test also increases the challenge. Includes pretests, posttests, and answer key