Divisibility Rules and Applications

The video tutorial explains how to determine if a number is divisible by 2, 3, 4, 5, 6, 8, 9, 10, and 12 using specific divisibility rules. It provides a step-by-step approach to check each number, using examples and logical reasoning to simplify the process without performing full division.

Which numbers are being tested for divisibility with 391,000?

• 2, 3, 4, 5, 6, 8, 9, 10, 12

• 3, 6, 9, 12, 15, 18, 21

• 1, 2, 3, 4, 5, 6, 7, 8, 9

• 2, 4, 6, 8, 10, 12, 14, 16

What is the rule for checking divisibility by 2?

• The sum of digits must be divisible by 3

• The last two digits must be divisible by 4

• The number must be even

• The number must end in 0 or 5

How can you determine if a number is divisible by 3?

• Check if the last two digits are divisible by 4

• Sum the digits and see if the result is divisible by 3

• Check if the number is even

• Check if the last digit is 0

What is the sum of the digits of 391,000?

• 19

• 27

• 15

• 21

What is the product of 3 and 9?

• 27

• 45

• 36

• 18

What is the rule for divisibility by 4?

• The number must end in 0

• The last two digits must be divisible by 4

• The sum of digits must be divisible by 3

• The number must be even

What must the last digit be for a number to be divisible by 5?

• 0 or 5

• Divisible by 3

• Odd

• Even

Why is 391,000 not divisible by 5?

• It ends in 8

• It ends in 5

• It ends in 1

• It ends in 0

How is divisibility by 6 determined?

• The last two digits must be divisible by 4

• The sum of digits must be divisible by 9

• The number must end in 0

• The number must be divisible by both 2 and 3

What digits are checked for divisibility by 8?

• The last two digits

• The sum of all digits

• The last digit

• The last three digits