Mastering Numbers: Factors, Multiples, Primes, and Composites

What are the factors of 12?

• 1, 2, 3, 4, 6, 12

• 1, 3, 5, 7, 9, 11

Answer explanation

The factors of 12 are 1, 2, 3, 4, 6, and 12. These numbers can divide 12 without leaving a remainder.

Tags

CCSS.4.OA.B.4

Nora, Benjamin, and Avery are counting their marbles. Nora has 15 marbles, Benjamin has 22 marbles, and Avery has 28 marbles. Which of them has a number of marbles that is a multiple of 5?

• Avery

• Nora

Answer explanation

The correct answer is 15 because it is divisible by 5.

Tags

CCSS.4.OA.B.4

Oliver found a number, 17, on a piece of paper. He is wondering if this number is a prime number. Can you help him?

• Yes

• No

Answer explanation

Yes, the number 17 is a prime number because it is only divisible by 1 and itself.

Tags

CCSS.4.OA.B.4

Which of the following numbers is composite?

• 3

• 4

Answer explanation

The number 4 is composite because it has factors other than 1 and itself. In this case, 2 is a factor of 4.

Tags

CCSS.4.OA.B.4

Daniel, Elijah, and Nora are playing a game where they have to jump on numbered tiles in a sequence. If they start at tile 7 and can only jump to the next tile that is a multiple of 7, what will be the first three tiles they land on?

• 7, 14, 21

• 21, 28, 35

Answer explanation

The first three multiples of 7 are 7, 14, and 21. These numbers are obtained by multiplying 7 by 1, 2, and 3 respectively. Therefore, the correct choice is 7, 14, 21.

Tags

CCSS.5.OA.B.3

Elijah, Arjun, and Jackson are sharing a pack of 30 candies. They are trying to divide the candies equally among them. Which of the following is NOT a possible number of candies each person can get?

• 3

• 11

Answer explanation

The number 11 is not a factor of 30 because it does not divide evenly into 30. The factors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30.

Tags

CCSS.4.OA.B.4

Is the number 51 prime or composite?

• Prime

• Composite

Answer explanation

The number 51 is composite because it has factors other than 1 and itself. In this case, 3 and 17 are factors of 51, making it composite.

Tags

CCSS.4.OA.B.4

Ethan, Rohan, and Mason are having a debate about prime numbers. Ethan says the smallest prime number is 0, Rohan says it's 1, Mason says it's 2, and a bystander says it's 3. Who is correct?

• Rohan (1)

• Mason (2)

Answer explanation

The smallest prime number is 2, as it is the only number among the answer choices that is divisible only by 1 and itself.

Tags

CCSS.4.OA.B.4

Which of the following numbers are factors of 42? (Choose all that apply)

• 6

• 7

• 11

• 14

Answer explanation

The factors of 42 are 6, 7, and 14. Therefore, the correct choices are 6, 7, and 14.

Tags

CCSS.4.OA.B.4

Anika, Kai, and Arjun are playing a game where they have to jump on tiles numbered in multiples of 9. If Kai is currently on tile 45, which tile should he jump on next?

• 54

• 63

Answer explanation

The next multiple of 9 after 45 is 54, which is the correct choice.

Tags

CCSS.3.OA.D.9