A number is divisible by 11 if the difference of the sum of its alternate digits is 0, 11 or multiple of 11.
Example 1:
Is 2343 divisible by 11?
The The alternate numbers are 2 3 4 3
Hence: (2 + 4) - (3 + 3) = 6 - 6 = 0
Since the difference is 0, the number 2343 is divisible by 11.
Hence: (2 + 4) - (3 + 3) = 6 - 6 = 0
Since the difference is 0, the number 2343 is divisible by 11.
Example 2:
Is 3640 divisible by 11?
The alternate numbers are 3 and 4 and 6 and 0
Hence: (3 + 4) - (6 + 0) = 7 - 6 = 1
Since the difference is 1, 3640 is NOT divisible by 11.
Hence: (3 + 4) - (6 + 0) = 7 - 6 = 1
Since the difference is 1, 3640 is NOT divisible by 11.
Student Exercise:
Try this: Is the Number 141570 divisible by 11?
Hint: The alternate numbers are (1,1,7) and (4,5,0).