Factoring Integers: Problem 6 

Rule 9: 
To factor an integer, simply break the integer down into a group
of numbers whose product equals the original number.  Factors are separated by multiplication signs.  Note that the number 1 is the factor of every number.  All factors of a number can be divided evenly into that number.

Problem 6: Is 7 a factor of 21? Why?
Answer.  Since 21 can be written as   
 , 7 is a factor.  Also   
  is an even division.

 S.O.S MATHematics home page 
