Identify and describe properties of prime, composite, square and triangular numbers(ACMNA122)


  • What a number is.
  • Numbers can be classified into different categories


  • That certain numbers can be classified by their properties..


    I can identify prime, composite, square and triangular numbers.

Essential Questions:

  • What are integers?
  • When do we work with integers in the real world?
  • Are there only positive numbers in the world?
  • Does adding two numbers always give me a positive answer?

Prime Numbers

Are numbers that only can be divided by 1 and itself.

For example, 13 is a prime number because it can only be divided by 1 and 13.

These are the prime numbers under 100.

Composite Numbers

Are numbers that have more than 2 factors. A factor is a number that can divide evenly into another number.

For example, 25 is a composite number because it can be divided evenly by 1 , 5 and 25.

These are the composite numbers under 100.

Square Numbers

Are numbers that form perfect squares. An easy way of finding square numbers is multiplying a number by itself.

For example, 1 x 1 = 1, 2 x 2 = 4, 3 x 3 = 9, 4 x 4 = 16. These are all square numbers.

Triangle Numbers

Are numbers that form perfect triangles.

Notice the pattern,

1+2 = 3
1+2+3 = 6
1+2+3+4 = 10
1+2+3+4+5 = 15

All the square numbers under 150.

Prime, Composite, Square and Triangle Numbers Videos

Student Generated Videos

Next Lesson