50 Missing Addends Worksheets upto Number 20, Ice Creams Popsicles Theme, Addition, Subtraction Activity, Kindergarten, 1st Grade No Prep Math Sub Plans. Standards: CCSS1.OA.A.1 CCSS1.OA.A.2 CCSS1.OA.B.4 CCSS1.OA.D.8 CCSSMP1 Has 50 pages for kids to practice their addition and subtraction skills. These sheets may also be useful for tests, revision exercise, sub plans, early finishers, extra work, sponge activity, homework packet and more.