Arithmetic Grade Four

Lesson One hundred and twenty-four: Divisibility

Multiples and count-bys are two names for the same kind of thing. Here are some examples: 

   8: 8, 16, 24, 32, 40, 48, 56, 64

   7: 7, 14, 21, 28, 35, 42, 49, 56

   4: 4, 8, 12, 16, 20, 24, 28, 32, 36
All the multiples of a number are also DIVISIBLE by that number. When number A is divisible by number B, there will be no remainder in the problem: number A divided by number B. Here are some examples: 

          NUMBER A	NUMBER B	ANSWER (none have remainders)

             48     /      8       =       6

             72     /      7       =       9

             21     /      3       =       7
Which of the following is not divisible by 5?
  1. 30
  2. 75
  3. 54
  4. 15
The correct answer is C. All the other answers are divisible by 5.

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