0
3 digits numbers: from 100 to 999
The first number greater than 100 and divisible by 7 is 105
The last number lower than 999 and divisible by 7 is is 987
(987-105)/7=126 intervals of 7-length
In fact 127 as numbers are to be counted, not intervals
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
Is seventytwo a multiple of three?
yes 72/3 equals 24. an easy way to find out if a number is divisible by three is to add up all the digits. if the sum of the digits is divisible by three, the whole number is divisible by three.
How do you find out if a number is divisible by three?
Add up the digits. If that total is a multiple of 3, so is the original number.
What are the divisible by 3?
If, when divided by 3, it leaves no remainder. Also, if you add the individual numbers up and that number is divisible by three, the larger one is as well. Example: 12345 adds up to 15. 15 is divisible by three. So is 12345.
How do you find out if a number is divisible by 4?
If the last two digits of a number are divisible by 4, the whole number is divisible by 4.
How do you know when a number is divisible by 3 and 9?
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.
What are the divisibility rules for 6 7 8 9 10?
If a number is divisible by six, then it must also be divisible by both two and three. To check it then, you simply apply both rules for each of those: Is it an even number? Is the sum of it's digits divisible by three? If both answers are yes, then the number is divisible by six. To find out if a number is divisible by seven take it's last digit, double it, and subtract it from the remaining digits. If the result is divisible by seven, then the original number is as well. For example is three 343 divisible by 7? Let's find out: 3 * 2 = 6, and 34 - 6 = 28. Is 28 divisible by seven? Yes, but if you're not sure, you can repeat the process. 8 * 2 = 16, 2 - 16 = -14. 14 is of course divisible by 7. If the last three digits of a number are divisible by 8, then the entire number is. For example, I know that 10923485710234985723908471859256 is divisible by eight, because I know that the last three digits, 256, form a number that's divisible by eight. Not sure about those last three digits? Simply divide them by two, three times in a row. If the result is a whole number, then it's divisible by eight. 256 / 2 = 128, 128 / 2 = 64, 64 / 2 = 32, so 256 is divisible by eight, and therefore 10923485710234985723908471859256 is also. If the sum of the digits is divisible by 9, then the number itself is. For example, is 8936523 divisible by 9? Well, 8 + 9 + 3 + 6 + 5 + 2 + 3 = 36. Is 36 divisible by 9? 3 + 6 = 9. 9 is obviously divisible by 9, so yes, 8936523 is also. If the last digit is a zero, then the number is divisible by 10. For example, 12340 is divisible by ten, but 12345 is not.
What is the divisibility rule for 9?
If you add up the digits, and the sum is divisible by 9 or a multiple of 9.* * * * *For really big numbers you may need to find the digital root (sum of digits) of the digital root.The divisibility rule for 9 is that the sum of the digits of a number must add up to 9 or a multiple of 9.For example, is 81 divisible by 9? Lets find out! 8+1=9. Then it is divisible by 9.
Is the number 1859 a prime number?
To find out if 1859 is a prime number, use the rules of division:1859 is not an even number, so it is not divisible by 2.The digits of 1859 add up to a number that is divisible by 3, so it is not divisible by 3.The last two digits (59) is not divisible by 4, so neither is 1859.The last digit is not 5, so it is not divisible by 5.1859 is not divisible by 2 and it is not divisible by 3, so it is not divisible by 6.When you double the last digit (9 doubled is 18), and subtract that number from the rest of the number (859 - 18 = 841), if the answer is 0 or divisible by 7, the number itself is divisible by 7. If you can't readily tell if the number is divisible by 7, you can do the steps again. Starting with 841, doubling the 1 is still 1, so take 1 away from 84 to get 83. 83 is not divisible by 7, so neither is 1859.The last three digits (859) are not divisible by 8, so 1859 is not divisible by 8.If the sum of the digits is divisible by 9, the number is divisible by 9. The sum of the digits is 23, which is not divisible by 9.1859 does not end with a 0, so it is not divisible by 10.If the sum of every second digit (8 + 9) minus the sum of the other digits (1 + 5) equals 0 or is divisible by 11, the number itself is divisible by 11. 17 - 6 = 11, so 1859 is divisible by 11.Since 1859 is divisible by 11, it is a composite number (a number that has at least three factors: 1, the number itself, and at least one oher factor).
How do you use divisibility rules to find at least for factors of a number?
Take the number 3336. You know it's divisible by 1 because everything is. You know it's divisible by 2 because it's even. You know it's divisible by 3 because the digits add up to a multiple of 3 and you know it's divisible by 4 because the last two digits are divisible by 4. So you've found at least four factors: 1,2,3 and 4.
Is 160 divisible by 9?
No it is not. To find out:Add the digits in the number (ex.- 1+6+0=7)If 7 is divisible by 9 (it is not) then the whole original number is divisible by nine.Hope i helped!;)
Could 3 go into 1065 evenly?
Yes. 3 * 355 is 1065. Here's is how you can tell is a number is divisible by three: the sum of the digits of the number you want to divide by three has to be divisible by three. Here's an example: You wanted to find if 3 could go into 1065 evenly. 1+0+6+5= 1+11= 12 12 is divisible by 3 (3 * 4), so 1065 is divisible by three.
How do you find out if a number is a multiple of 3?
you add up the digits, and if the sum is a multiple of 3, then the number is divisible by 3!
