Number Theory Flashcard

Front

What is the divisibility rule for 3?

Back

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

Front

What does NOT show 7²?

Back

14

Front

Prime numbers have _____ factors.

Back

2

Front

What is the GCF of 20 and 32?

Back

4

Front

List 5 multiples for 8.

Back

8, 16, 24, 32, 40

Front

What is a prime number?

Back

A number greater than 1 that has no positive divisors other than 1 and itself.

Front

What is the least common multiple (LCM) of 4 and 5?

Back

20

Front

What is the definition of a composite number?

Back

A number that has more than two distinct positive divisors.

Front

What is the divisibility rule for 5?

Back

A number is divisible by 5 if its last digit is 0 or 5.

Front

What is the sum of the first 5 prime numbers?

Back

28 (2 + 3 + 5 + 7 + 11 = 28)