15 15 15 15 15
+10 +20 +30 +40 +50
--- --- --- --- ---
25 35 45 55 65
28 28 28 28 28
+10 +20 +30 +40 +50
--- --- --- --- ---
38 48 58 68 78
NOTE:
Point out to the student that the digits in the one's column can be added
separately from the digits in the ten's column. Make a few more problems
like these and solve them with the student.