Step 2: Teach Lesson
Write the following story problem on the board and ask the student to solve the problem using any other method that they
Chelsea bought 16 pieces of bubblegum and 9 jawbreakers at the store. How many pieces of candy
did she have altogether?
After the student had an opportunity to solve the problem using their manipulatives, ask the student to share how they
solved the problem. Write the steps on the board as students explain their methods.
Explain to the student that there are many methods to solving an addition problem. One strategy is the “Expanded Form.”
The student write the numbers in expanded form first and then add the different place values. The answers from each of
the places are then added together. Watch Video 1 in Step 1
Another strategy is “Carry Over Form”. The student adds each number in the place value column and carry’s over the
reminder. Watch Video 2 in Step 1
Write 6 double digit math problems on the board or a piece of paper and have the student solve half of the problems using
the expanded form and the other half using the carry over form. Observe the student. After the student has correct solved
all 6 problems ask the student which method they prefer and why.