This unit teaches 1st Grade Common Core Math Standards 1.OA.7 and 1.OA.8. 1.OA.7 teaches students to apply the equal sign to determine if equations involving addition and subtraction are equal. 1.OA.8 teaches students to determine the unknown whole number in an addition or subtraction equation involving three whole numbers. This 18 lesson unit has lesson plans for each lesson, a student booklet with practice pages for each lesson, 3 tests, a unit test, homework practice pages, games and c