No, not all numbers are divisible by 3. A number is divisible by 3 if the sum of its digits is divisible by 3. For example, the number 495 is divisible by 3 because 4 + 9 + 5 = 18, and 18 is divisible by 3. However, numbers like 5, 7, and 11 are not divisible by 3 because the sum of their digits is not divisible by 3.
Here are some examples of numbers that are and are not divisible by 3:
- Divisible by 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30...
- Not divisible by 3: 1, 2, 4, 5, 7, 8, 10, 11, 13, 14...
The divisibility rule of 3 is a handy trick for quickly determining whether a number is divisible by 3 without having to perform long division. This rule applies to all whole numbers, whether they are positive or negative.
