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Stage 14 of 20

Two-Digit Subtraction (With Borrow)

The final subtraction challenge: borrowing across columns in two-digit problems. Combine all prior skills for accurate, rapid mental subtraction.

What You'll Learn

  • Borrow across ones and tens columns fluently
  • Use the add-up method as an alternative strategy
  • Solve problems like 72 − 38 entirely in your head

Explanation

For 72 − 38: ones need borrowing. 72 = 60 + 12. 12 − 8 = 4. Tens: 6 − 3 = 3. Answer: 34.

Add-up: 38 → 40 (2), 40 → 70 (30), 70 → 72 (2). Total: 34.

When the tens digit is 0 after borrowing (e.g., 80 − 47), treat it as the lower decade: 70 + 10 − 47.

Continuous borrowing (503 − 187) extends this logic to three digits — the pattern is identical.

Pro Tips

  • • For mental math, the add-up method is often faster and less error-prone.
  • • Estimate first: 72 − 38 ≈ 70 − 40 = 30. Answer near 30 is expected.
  • • Check with addition: 34 + 38 = 72.

Practice Exercises

Work through each problem mentally. Click "Show Answer" when you're ready to check.

  1. 1. 72 − 38 = ?
  2. 2. 61 − 27 = ?
  3. 3. 80 − 47 = ?
  4. 4. 53 − 29 = ?
  5. 5. 90 − 56 = ?
  6. 6. 45 − 18 = ?
  7. 7. 70 − 35 = ?
  8. 8. 64 − 39 = ?
  9. 9. 91 − 48 = ?
  10. 10. 55 − 17 = ?