Mathematics - Addition and Subtraction - Two-digit subtraction with regrouping - Borrow and Subtract
Vertical subtraction problems requiring borrowing. Interface shows: original tens digit, crossed-out tens digit (after borrowing), modified ones digit (with borrowed 10 added), ones answer, tens answer. Student fills step by step. 12 problems. Examples: 45-18, 73-29, 81-47, 50-23. If student tries t