10 + 2 = 12
10 + 5 = 15
10 + 7 = 17
NOTE: Point out the pattern shown in these examples where the one digit
number winds up in the one's column of the answer. Mention the term
"expanded notation" and briefly explain, for example, that 15 = 10 + 5 and
that 10 + 5 is the expanded notation form of 15, but don't dwell on this
term "expanded notation" too much. Just prepare the student to find the answers to problems like those
shown above.