Number Theory Quiz

Prime numbers have _____ factors.

• no

• 3

• 1

• 2

Use a factor tree to find prime factorization of 24.

• 2 x 3 x 2 x 3

• 2 x 3 x 2 x 2

• 6 x 2 x 2

• 2 x 3 x 4

Tags

CCSS.4.OA.B.4

What is the divisibility rule for 3?

• Add up the digits. The sum must be even and divisible by 3.

• The digits must add up to 9.

• The last digit must be a 3.

• Add up the digits. The sum must be divisible by 3.

List the factors of 12 & 20, then identify the greatest common factor.
12-
20-
GCF=

• 12- 1, 2, 5, 7  20-10, 20, 30, 40 GCF 10
• 12-1, 12, 24, 36  20-20, 40, 60, 80 GCF 40
• 12-2, 4, 6   20-1, 10, 20 GCF 20
• 12-1, 2, 3, 4, 6, 12  20-1, 2, 4,5,10, 20 GCF 4

Tags

CCSS.6.NS.B.4

What is the prime factorization of 56?

• 3² x 6

• 2³ x 7

• 2⁴ x 6

• 3³ x 2

Find the least common multiple of 15 and 20

• 120

• 100

• 300

• 60

Evaluate (-5)²

• -25

• 25

Evaluate -5²

• -25

• 25

What is a composite number?

• A number with less than 2 factors
• A number with exactly 2 factors
• A number with more than 2 factors
• A number that can be divided evenly with no remainder

What is a prime number?

• A number with less than 2 factors
• A number with exactly 2 factors
• A number with more than 2 factors
• A number that can be divided evenly