Understanding the Rule for Divisibility by 3

When it comes to divisibility by 3, the rule is fairly straightforward. A number is divisible by 3 if the sum of its digits is also divisible by 3. For example, take the number 123. The sum of its digits is 1 + 2 + 3 = 6, which is divisible by 3. Therefore, 123 is also divisible by 3. This rule can prove to be quite handy when working with larger numbers. It's a simple yet powerful tool in the study of number theory, and understanding it can greatly assist students in their mathematical journey.