Students use disk models to scaffold column subtraction and solve equations where exchanging into the tens is a necessary step
A. Solve subtraction problems using disk models
B. Use disk models to support solving column subtraction
C. Solve column subtraction with scaffolding
D. Use disk models to practice exchanging into the tens
E. Solve subtraction problems with regrouping (Level 1)
G. Solve subtraction problems with regrouping (Level 3)
H. Solve subtraction problems with regrouping (Level 4)
I. Solve column subtraction, making decisions about exchanging into the tens
J. Practice solving column subtraction problems independently (Part 1)
K. Practice solving column subtraction problems independently (Part 2)
L. Solve column subtraction problems with 2- and 3-digit components (Level 1)
M. Solve column subtraction problems with 2- and 3-digit components (Level 2)
N. Solve column subtraction problems with 2- and 3-digit components (Level 3)