Mastering Long Division Techniques

Sep 30, 2024

Math Antics - Long Division

Introduction

  • Overview of long division with multi-digit dividends.
  • Key concept: Break down big division problems into smaller, easier steps.
  • Focus on digit-by-digit division.

Example Problems

Problem with One-Digit Divisor

  • First example:
    • Question: How many 2's fit into 5?
    • Answer: 2 (2 x 2 = 4, remainder 1).
    • Next digit: Combine with remainder to make 12.
    • Answer: 6 (2 x 6 = 12, no remainder).
    • Final digit: 8 (Answer: 4, 2 x 4 = 8, no remainder).
    • Final answer: 264.

Problem with Larger Divisor

  • Second example:
    • Question: How many 8's fit into 5?
    • Answer: None, 8 is too big.
    • Group first two digits (52) and ask how many 8's fit into 52.
    • Answer: 6 (6 x 8 = 48, remainder 4).
    • Final digit: Combine remainder and last digit (48).
    • Answer: 6 (6 x 8 = 48, no remainder).
    • Final answer: 66.

Key Takeaways

  • When the divisor is bigger than the first digit of the dividend, group more digits.
  • You can take larger chunks of the dividend to minimize steps, but it makes the division harder.
  • Fewer steps may seem appealing, but each step can be more challenging.

Division with Two-Digit Divisors

  • New examples with two-digit divisors:
    • First problem (24 into 528):
      • Group first two digits (52).
      • Estimate (2 x 24 = 48, remainder 4).
      • Bring down last digit (4).
      • Answer: 22.
    • Second problem (88 into 528):
      • Group first three digits (528).
      • Estimate (6 x 88 = 528, no remainder).
      • Final answer: 6.

Long Division Procedure with Two-Digit Divisors

  • Example: 817,152 divided by 38.
    1. Group first two digits (81).
    2. Estimate (2 x 38 = 76, remainder 5).
    3. Bring down next digit (5) and combine (57).
    4. Estimate (1 x 38 = 38, remainder 19).
    5. Bring down 1 (191).
    6. Estimate (5 x 38 = 190, remainder 1).
    7. Bring down 2 (152).
    8. Estimate (4 x 38 = 152, no remainder).
    • Final answer: 21,432.

Conclusion

  • Importance of estimating and rounding in division problems.

  • Long division steps become more complex with larger divisors.

  • Encouragement to use calculators for complex problems.

  • Reminder: Math is about problem-solving, not just division.

  • For more resources: mathantics.com