Which of the following shows 24 as a product of its primes?

• 1, 2, 3, 4, 6, 12

• 2 x 12

• 2 x 2 x 3

• 4 x 3

• 24, 48, 72, ...

Answer explanation

Some of the other ones look correct but are not all prime numbers. Remember primes can only be divisible by one and themselves.

Which of the following numbers are common factors of both 24 and 36?

Choose all that apply.

• 2

• 3

• 4

• 6

• 12

Answer explanation

You can use divisibility tricks to check without actually dividing the numbers.

Tags

CCSS.4.OA.B.4

Which of the following shows the difference between the cube of 9 and the square of 7?

Which of the following shows the cube of 7?

• 7x7x7

• 343

• 21

• 7 x 3

• 49

Tags

CCSS.8.EE.A.2

• 50

• 49

• 64

• 214

• 0

Tags

CCSS.6.EE.A.1

The prime factorization of 21 is 3 x 7.

What is the prime factorization of 210?

• 2 x 3 x 5 x 7

• 21 x 10

• 3 x 7 x 10

• 1 x 3 x 7 x 10

• 2 x 2 x 3 x 5 x 5 x 7

What is the greatest common factor of 12, 18, 20?

12 = 2 x 2 x 3

18 = 2 x 3 x 3

20 = 2 x 2 x 5

• 2

• 4

• 6

• 3

• 10

What is the least common multiple of 12, 18, 20?

12 = 2 x 2 x 3

18 = 2 x 3 x 3

20 = 2 x 2 x 5

• 2

• 180

• 4320

• 60

• 90

• 46

• 529

• 409

• 429

• 92

Tags

CCSS.6.EE.A.1

• 144 - 36

• 36 x 27

• 144 - 27

• 36 + 27

• 144 x 36

Tags

CCSS.7.EE.B.3