Divisibility Rules Checker
How It Works
This divisibility rules checker uses established formulas to provide accurate results.
The basic rule:
- Divisible by 2: last digit is 0, 2, 4, 6, or 8
- Divisible by 3: sum of digits is divisible by 3
- Divisible by 5: last digit is 0 or 5
- Divisible by 9: sum of digits is divisible by 9
Results are estimates. Consult a professional for critical decisions.
Frequently Asked Questions
What are divisibility rules?
Divisibility rules are shortcuts to determine if a number divides evenly without doing long division. For example, a number is divisible by 2 if its last digit is even, by 3 if the sum of its digits is divisible by 3, and by 5 if it ends in 0 or 5.
How do you check divisibility by 4?
A number is divisible by 4 if its last two digits form a number divisible by 4. For example, 316: the last two digits are 16, and 16 ÷ 4 = 4, so 316 is divisible by 4.
How do you check divisibility by 6?
A number is divisible by 6 if it is divisible by BOTH 2 and 3. For example, 42 is even (divisible by 2) and 4+2=6 is divisible by 3, so 42 is divisible by 6.
What is the divisibility rule for 9?
A number is divisible by 9 if the sum of its digits is divisible by 9. For example, 729: 7+2+9 = 18, and 18 is divisible by 9, so 729 is divisible by 9.