Types of Number Worksheets – New & Engaging

What Are Triangle Numbers?

Triangle numbers are a special type of number.  Triangle numbers are also called triangular numbers. Triangular numbers start from 1 and increase incrementally. The second triangular number is 3. The third triangle number is 6.

Triangle numbers are arranged as dots in a right angle triangle. Triangle numbers can also be arranged as small equilateral triangles.

The image below shows the list of the first 9 triangle numbers.

What Is A Prime Number?

A prime number has two factors, one and itself. For example 3 has factors 1 and 3. 4 has factors 1, 2 and 4. Therefore 3 is prime number whereas 4 is not a prime number. Number that are not prime are known as composite numbers. The image below shows prime numbers highlighted in green. 5 is a prime number, however 6 is a composite number.

List of Prime Numbers

The image below shows a grid of prime numbers between 1 and 100. 2 is the only even prime number. 2 is also the smallest prime number. 1 is not a prime number since it only has one factor, 1. The highest prime number is 97. The prime numbers have been shaded yellow.