Tell whether each number is divisible by 2, 3, 4, 5, 8, 9, or 10. Some numbers may be divisible by more than one number. 1.324
2.840
3.2,724
4.81,816
5.7,848
We'll be glad to check your answers.
i think 840 is divisible by 10
and 7,848 divisible by 2??
What other numbers goes into 840 besides 10?
Try them out.
Yes, 7,848 is divisible by 2 --and four more numbers.
840:5,2
I sure hope that they still teach the following simple divisibility checks:
- to be divisible by 2, the number must be even
- to be divisible by 3, add up the digits of the number, if
the sum is divisible by 3, so is the number
- to be divisible by 4 , the last two digits must be 00 or the last two digits
must be divisible by 4 , e.g. 840
- to be divisible by 5, the number must end in either 0 or 5
- to be divisible by 8 , the last 3 digits of the number must be divisible by 8
- to be divisible by 9, add up the digits of the number, if
the sum is divisible by 9 , so is the number
- to be divisible by 10, the number must end in 0
I will do the 2,724
it is even, so divisible by 2
sum is 2+7+2+4 = 15 , so divisible by 3
last two digits are divisible by 4 , so divisible by 4
does not end in 0 or 5, so NOT divisible by 5
last 3 digits Not divisible by 8 , so NOT divisible by 8
last digit is not 0 , so NOT divisible by 10
repeat for the other numbers, you could always check with your calculator.