Divisibility Rules and Number Theory Quiz

What is the fundamental principle for determining if a number is divisible by 9?

• The number must end in 5
• The number must be even
• The last digit must be zero
• The sum of its digits must be divisible by 9

Which of the following is a reliable method to check divisibility by 4?

• The number ends in 0
• The last digit is even
• The sum of digits is divisible by 4
• The last two digits form a number divisible by 4

To determine if a number is divisible by 5, what specific characteristic must the number have?

• Must end in 0 or 5
• Must be an even number
• Must have a sum of digits divisible by 5
• Must be greater than 100

What is the divisibility rule for checking if a number is divisible by 3?

• The number must end in 5
• The number must be even
• The sum of its digits must be divisible by 3
• The last digit must be zero

If a number is divisible by both 2 and 3, it is guaranteed to be divisible by:

• 12
• 9
• 15
• 6

What is the quickest way to determine if a number is divisible by 10?

• The number is even
• The number ends in 0
• The last two digits are divisible by 10
• The sum of digits is divisible by 10

For a number to be divisible by 8, what condition must its last three digits satisfy?

• Must end in 0
• Must be an even number
• Must be divisible by 2
• Must be divisible by 8

What is the divisibility rule for checking if a number is divisible by 11?

• The number must be even
• Alternate digits sum must be divisible by 11
• The last digit must be zero
• The sum of all digits must be divisible by 11

If a number is divisible by both 3 and 5, it is guaranteed to be divisible by:

• 6
• 15
• 30
• 10

What makes a number divisible by 2?

• It is greater than 10
• Its sum of digits is even
• It ends in an even digit
• It ends in 5