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Understanding Multiples and Factors in Math

Nov 3, 2024

Lecture Notes: Understanding Multiples and Factors

Multiples

  • Definition: Multiples are essentially the times tables of a number.
  • Example with 6:
    • First five multiples: 6, 12, 18, 24, 30.
    • All multiples of a number are divisible by that number without a remainder.
    • Example:
      • 18 is a multiple of 6 because 18 ÷ 6 = 3.
      • 19 is not a multiple of 6 because 19 ÷ 6 = 3 R1 (remainder 1).
  • Checking for Multiples:
    • To check if a big number is a multiple, divide it by the target number.
    • Example:
      • 378 ÷ 6 = 63, so 378 is a multiple of 6.
      • 412 ÷ 6 = 68.6 (not a whole number), so 412 is not a multiple of 6.
  • Alternating Method:
    • Keep adding the number to find its multiples.
    • Example with 14: 14, 28, 42, 56, 70, etc.

Factors

  • Definition: Factors are numbers that multiply together to make another number.
  • Factor Pairs:
    • Example with 28:
      • Factor pairs: 1 x 28, 2 x 14, 4 x 7.
      • These numbers (1, 2, 4, 7, 14, 28) are factors of 28.
  • Checking for Factors:
    • A number is a factor if it divides into another number without a remainder.
    • Example:
      • 4 is a factor of 28 because 28 ÷ 4 = 7.
      • 5 is not a factor of 28 because 28 ÷ 5 = 5.6.
  • Finding Factors:
    • List factor pairs starting with 1 and the number itself.
    • Example with 48:
      • Factor pairs: 1 x 48, 2 x 24, 3 x 16, 4 x 12, 6 x 8.
      • Factors: 1, 2, 3, 4, 6, 8, 12, 16, 24, 48.
    • Example with 50:
      • Factor pairs: 1 x 50, 2 x 25, 5 x 10.
      • Factors: 1, 2, 5, 10, 25, 50.

Key Points

  • Multiples vs. Factors:
    • Multiples are larger numbers a number can multiply to.
    • Factors are smaller numbers that divide into the number.
  • Example with 12:
    • Multiples: 24, 36, 48, etc.
    • Factors: 1, 2, 3, 4, 6, 12.
  • Important Note:
    • The number itself is both a multiple and a factor.

Conclusion

  • Be clear on the difference between multiples and factors.
  • Remembering the number itself counts as both a multiple and a factor is essential.
  • Understanding these concepts will help avoid confusion during exams.

End of Lecture