Math Extension Units grades 23 Author:Sharon Eckert, Judy Leimbach Four great units will provide hours of activities that will allow students who have already mastered the basic concepts to work independently or in small groups to extend their knowledge and apply their skills. Each unit includes 13-14 attractive reproducible worksheets, making this an easy way for busy instructors to provide challengi... more »ng, enriching experiences for able primary math students. Place Value, Problem Solving, Money, Time and Measurement. Grades 2-3.« less