Worked example: Subtracting 3-digit numbers (regrouping from 0)
imp-addition-and-subtraction--imp-subtracting-with-regrouping-within-1000--regrouping-from-0-when-subtracting-three-digit-numbers
Addition, subtraction, and estimation
Subtracting with regrouping within 1000
Sal has to borrow from a 0 to subtract 301-164.