Make 2nd Grade Subtraction Practice Feel Like Play

Borrowing arrives in second grade and brings the most persistent error in elementary arithmetic: seeing 3 − 7, finding it impossible, and quietly answering 4. It is a direction error, not an arithmetic one. The habit worth building now is checking by adding the answer back to the number subtracted, which catches it every time.

Second grade is the written-method year. Column addition and subtraction arrive, then regrouping, and with them the first arithmetic that has a procedure to follow rather than a fact to recall. Children who still lack instant facts within 20 find this year disproportionately hard, because they are running a procedure and reconstructing facts at the same time.

2nd graders are expected to subtract two-digit numbers in columns and begin borrowing, checking answers by adding back; after that comes two-digit column subtraction, then borrowing.

Watch for subtracting the smaller digit from the larger one regardless of which is on top.