Unit 4: Unit review - Categories of numbers

What is a prime number?

• a number that has only two factors: itself and 1

• a number with more than two factors

• the answer you get when you multiply a number by itself.

Which of the following are prime numbers?

(Choose all that apply.)

• 1

• 5

• 10

• 13

Is 2 prime or composite?

• prime

• composite

Is 17 prime or composite?

• prime

• composite

Is 24 prime or composite?

• prime

• composite

Is 25 prime or composite?

• prime

• composite

Is 33 prime or composite?

• prime

• composite

Which numbers are factors of 20?

(Choose all that apply.)

• 1

• 2

• 3

• 4

• 5

Why is a 'square number' called a 'square number'?

• Its array is made up of lots of little squares.

• Its array can be in the shape of a square.

• You can only make it using squares, not other shapes.

What does 3² mean?

(Choose all that apply.)

• 3x2

• 3x3

• 3 squared

• 9