Winter, 100 First Grade Subtraction upto 20 Worksheets, 100 First Grade Math Test Prep, 100 Common Core Grade 1 Math Activities, First Grade Math Sub Plan 1.OA.C.6 Subtract within 20 Size: Letter Paper sheet. It has 100 pages. Each sheet has 12 Equations. Answer Sheet for Teacher included. Math Subtraction Worksheet Pack up to 20 has many uses. It can be used for: In-Class Practice Homework Assignments Small Group Activities Formative Assessments Math Centers Timed Drills Interactive Games Individualized Learning Progress Monitoring