Practice problems:
1. What are the two main goals for teaching 2-digit addition and subtraction (or almost anything else in math)
2. How should a lesson be structured so that the teacher demonstration is effective?
3. What are some advantages of using base 10 manipulatives to teach 2-digit addition and subtraction?
3. What is the key point in using manipulatives to teach 2-digit addition and subtraction?
4. Put these lessons in order:
a. adding using both manipulatives and pencil and paper
b. adding using just manipulatives, without exchanging
c. adding using just manipulatives with exchanging
d. adding using only pencil and paper