add all digits in a number together over and over until you can't anymore and if that's divisible by three the whole number is divisible by three.
eg: is 324 divisible by three? let's find out. 3+2+4=? 3
2
+4
___
9
and since 9 is divisible by three so is 324.
same rule applies with 9.
Wiki User
∙ 13y agoIf a number is not divisible by 3 then it is not divisible by 9.
If a number is even, it's divisible by two. If the digits of a number add up to a multiple of 3, it's a multiple of 3. For example, 342 is divisible by 3 because 3 + 4 + 2 = 9 and 9 is divisible by 3.
To check for divisibility by 9 sum the digits of the number and if this sum is divisible by 9 then so is the original number. For 32643: 3 + 2 + 6 + 4 + 3 = 18 which is divisible by 9 so 32643 is divisible by 9. As 9 = 3 × 3, any number divisible by 9 is also divisible by 3, thus as 32643 is divisible by 9 it is also divisible by 3. However, for completeness: to check for divisibility by 3 sum the digits of the number and if this sum is divisible by 3 then so is the original number. For 32643: 3 + 2 + 6 + 4 + 3 = 18 which is divisible by 3 so 32643 is divisible by 3.
There are many numbers between 500 and 1000 divisible by 3 and 9. Any number divisible by 9 is divisible by 3. How about 900?
999 is divisible by 9, but not by six; the next lower number divisible by 9 is 990, which is also divisible by 6, so that's the answer. Some shortcuts for divisibility: 0 is divisible by any number. If the last digit of a number is divisible by 2, the number itself is divisible by 2. If the sum of the digits of a number is divisible by 3, the number itself is divisible by 3. If the last TWO digits of a number are divisible by 4, the number itself is divisible by 4. If the last digit of a number is divisible by 5, the number itself is divisible by 5. If a number is divisible by both 2 and 3, it is divisible by 6. If the last THREE digits of a number are divisible by 8, the number itself is divisible by 8. If the sum of the digits of a number is divisible by 9, the number itself is divisible by 9. 990: 9+9+0=18, which is divisible by 9, so 990 is divisible by 9. 18 is also divisible by 3, so 990 is divisible by 3, and since 990 ends in 0 it's also divisible by 2, meaning that it's divisible by 6 as well.
add all the digits of the number and check if it is divisible by 3. eg-3321=3+3+2+1=9=divisible by three.the same works for 9.
If a number is not divisible by 3 then it is not divisible by 9.
If a number is even, it's divisible by two. If the digits of a number add up to a multiple of 3, it's a multiple of 3. For example, 342 is divisible by 3 because 3 + 4 + 2 = 9 and 9 is divisible by 3.
Yes, any number divisible by 9 is also divisible by 3.
Yes, every number that's divisible by 9 is divisible by 3
yes, you know that because if you add the digits together and that number is divisible by 9, then that large number is divisible by 9. 3+4+2 is 9, which is divisible by 9. conclusion 342 is divisible by 9.
If the sum of the digits can be divided by 3. 93 is divisible by 3 because 9+3=12 we know 12 is divisible by 3 because 1+2=3 so the number is divisible by 3.
To check for divisibility by 9 sum the digits of the number and if this sum is divisible by 9 then so is the original number. For 32643: 3 + 2 + 6 + 4 + 3 = 18 which is divisible by 9 so 32643 is divisible by 9. As 9 = 3 × 3, any number divisible by 9 is also divisible by 3, thus as 32643 is divisible by 9 it is also divisible by 3. However, for completeness: to check for divisibility by 3 sum the digits of the number and if this sum is divisible by 3 then so is the original number. For 32643: 3 + 2 + 6 + 4 + 3 = 18 which is divisible by 3 so 32643 is divisible by 3.
There are many numbers between 500 and 1000 divisible by 3 and 9. Any number divisible by 9 is divisible by 3. How about 900?
999 is divisible by 9, but not by six; the next lower number divisible by 9 is 990, which is also divisible by 6, so that's the answer. Some shortcuts for divisibility: 0 is divisible by any number. If the last digit of a number is divisible by 2, the number itself is divisible by 2. If the sum of the digits of a number is divisible by 3, the number itself is divisible by 3. If the last TWO digits of a number are divisible by 4, the number itself is divisible by 4. If the last digit of a number is divisible by 5, the number itself is divisible by 5. If a number is divisible by both 2 and 3, it is divisible by 6. If the last THREE digits of a number are divisible by 8, the number itself is divisible by 8. If the sum of the digits of a number is divisible by 9, the number itself is divisible by 9. 990: 9+9+0=18, which is divisible by 9, so 990 is divisible by 9. 18 is also divisible by 3, so 990 is divisible by 3, and since 990 ends in 0 it's also divisible by 2, meaning that it's divisible by 6 as well.
It is impossible since 3 can already go into 9.
3 and 9. 93 has a digit sum of 12, initially, which is divisible by 3, but not by 9. So 93 is divisible by 3, but not by 9. 99 has a digit sum of 18, initially, which is divisible by 3 and 9. So 99 is divisible by both 3 and 9.