Addition and subtraction are the first two operations kids learn. They must learn that when 2 numbers are added, the result is a number with a GREATER value and when 2 numbers are subtracted, the answer is a number with LESSER value. Be sure you have a number line posted in your classroom--or better yet, create one with the help of students and then post it--so that students can see addition and subtraction in a vertical format. Please see below for a selection of Leveled Lessons for Below Level (basic), and/or On Level (median), and/or Above Level (competent) readers.