The CCSS.MATH.1.OA.C.5 worksheets with answers for 1st grade students to practice problems on Add and subtract within 20 using strategies such as counting on, counting back, making 10, using fact families and related known facts, and composing or decomposing numbers with an emphasis on making ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1=9 or adding 6 + 7 by creating the known equivalent 6 + 4 + 3 = 10 + 3 = 13) is available online for free in printable and downloadable (pdf & image) format. For more questions and answers on 1.OA.C.5 math activities, tap on generate new worksheet to learn, practice, test and verify math skills under the common core cluster (1OAC) add and subtract within 20 in domain operations and algebraic thinking.
Objective:
To practice these math problems of 1OAC worksheets, students are required to add and subtract within 20 using strategies such as counting on, counting back, making 10, using fact families and related known facts, and composing or decomposing numbers with an emphasis on making ten. Users can directly refer the answer key to verify the work with steps for the corresponding practice problems given in the 1.OA.C.5 activities under the domain operations and algebraic thinking in common core state standards for 1st grade mathematics. The main objective of these 1.OA.C.5 practice problems and answers is to make students to understand how to (1OAC) add and subtract within 20.