Subtract two four-digit numbers both with and without regrouping. Use column subtraction with the help of disks in a place value chart to visualize the regrouping and the subtraction
B. Subtract multi-digit numbers with regrouping in multiple places using column subtraction
C. Subtract multi-digit numbers with regrouping across zeros using column subtraction
D. Subtract multi-digit numbers using the standard algorithm
E. Pretest. Finding the Area and Perimeter of a Rectangle