Practice subtracting three-digit numbers that require more than one regrouping using the standard algorithm
A. Solve 3-digit column subtraction with exchanging with and without using a disk model
C. Model 2-step exchanges in subtraction problems using a disk model
D. Solve 3-digit column subtraction with 2-step exchanges with and without using a disk model
E. Solve 3-digit column subtraction with 2-step exchanges