Question 198428: We know that for a number to be divisible by 3, we have to add up the individual digits and check if it is divisible by 3, for example, 21 is divisible by 3 as the digits 2+1=3 is divisible by 3. Without the calculator, are there ways to check divisibility by 2, 4, 5, 6, 7, 8, 9?
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website! Divisibility by 2: If the number ends with a 0, 2, 4, 6, or 8, then the number is divisible by 2.
Examples: 24, 36, 72, 98, and 1020 are all divisible by 2
Divisibility by 4: If the last two digits of a number is divisible by 4, then the number is divisible by 4.
Examples: 1024, 120, 156, and 236 are all divisible by 4 (since 24, 20, 56, and 36 are divisible by 4)
Divisibility by 5: If the number ends with a 0 or a 5, then the number is divisible by 5.
Examples: 25, 35, 70, 95, and 120 are all divisible by 5
Divisibility by 6: If a number is divisible by 2 AND divisible by 3, then it is divisible by 6. So use the divisibility rules for 2 and 3.
Divisibility by 7: The rule is a bit tricky, check out this link to find out more: http://argyll.epsb.ca/jreed/math7/strand1/1104.htm
Divisibility by 8: If the last three digits of a number are divisible by 8, then the number itself is divisible by 8
Ex: 1,704 is divisible by 8 since 704 is divisible by 8
Divisibility by 9: If the digits add up to a multiple of 9, then the number is divisible by 9
Example: 126 is divisible by 9 since 1+2+6=9
|
|
|
