This common-core aligned math unit guides students through the process of adding and subtracting numbers through 20 by making ten and decomposing ten. This unit features worksheets to help students practice counting on from 10, writing and identifying numbers up to 20. They must circle groups of 10 and count on to identify quantities. It also includes worksheets to help students apply their understanding of place value to add 10 to single-digit numbers. There are differentiated worksheets designed to help students apply strategies of making ten and decomposing ten to add and subtract. Plus, I included a unit test!