Divisibility by Three Concepts

The video tutorial explains the divisibility rule for three, which states that a whole number is divisible by three if the sum of its digits is divisible by three. The tutorial provides examples to illustrate this rule, showing numbers that are and are not divisible by three. It concludes with an interactive exercise encouraging students to apply the rule to determine the divisibility of various numbers.

What is the key concept of the divisibility rule for three?

• A number is divisible by three if it ends in 3.

• A number is divisible by three if the sum of its digits is divisible by three.

• A number is divisible by three if it is an even number.

• A number is divisible by three if it is a prime number.

Which of the following numbers is divisible by three?

• 242

• 13

• 724

• 84

Why is the number 8 not divisible by three?

• Because it is a prime number.

• Because the sum of its digits is not divisible by three.

• Because it ends in an even digit.

• Because it is an even number.

Which of the following numbers is not divisible by three?

• 181

• 18

• 62

• 12

What should you do to determine if a number is divisible by three?

• Sum the digits and see if the result is divisible by three.

• Check if the number ends in three.

• Check if the number is even.

• Check if the number is a multiple of six.