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### Course: Pre-algebra>Unit 1

Lesson 1: Factors and multiples

# Reasoning about factors and multiples

Use the equation 3x5=15 to understand the relationship between factors and multiples. Created by Sal Khan.

## Want to join the conversation?

• um... whats a factor of 78 plz help im cofuzed🤔
• The factors of 78 are 1,2,3,6,13,26,39,78.
To figure these out be sure to check the previous lesson on divisibility checks.
• how do i do fector pair?
• You don't exactly do factor pairs. The factor pairs of a number are various pairs of numbers that when multiplied will get you to that number. So, say with prime numbers, there's only one factor pair: 1 and itself. For composite numbers, the factors are more than two. So, answering your question, the factor pairs of a number will always be easy to figure out once you know what type of number it is. To organize a factor pair, just type\write say for 67, 1 and 67 or 1x67.
• what are factors of 82?
• 82 is a composite number and has 4 factors which are 1, 2, 41 and 82!

Happy Learning!
• wait if a multiple of 20 is 5 and 4 than a factor of 20 would be 5 and 4 how the heck am i supposed to know what is wich
• Multiples of 20 are 20, 40, 60, etc.
Factors of 20 are 1, 2, 4, 5, 10, 20
(1 vote)
• so i just can use multiples?
• What is a factor of 76 I’m really confused
• The factors of 76 are 1, 2, 4, 19, 38, and 76.
• what is a factor of 138 pls help
me