Practice problems:
1. What are the concepts and skills children need to be able to use the build up through ten to subtract strategy?
2. Which facts can be efficiently solved using the build up through ten to subtract strategy?
3. Solve 15-8 using the build up through ten to subtract strategy. Represent your solution process using:
a. ten frames
b. an open number line
c. Cuisenaire rods
d. number sentences (equations)