Number Blocks: Triangular Numbers


Triangular numbers, or triangle numbers, are a sequence of numbers that can be represented by a pattern of objects arranged in an equilateral triangle. The numbers of this sequence are 1, 3, 6, 10, 15, 21, 28, 36, and so on. The n-th triangular number is equal to the sum of the n natural numbers from 1 to n. The concept of triangle numbers is introduced to kids in secondary school. But this knowledge is quite useful for kids in fifth grade and above to solve many other math problems. Learning triangle numbers can help kids develop their ability to recognize patterns, understand number formulas, and discover relationships between geometric shapes and numbers.

This worksheet shows the first few triangle numbers illustrated by number blocks and their corresponding calculations. It is easy to see the pattern that one more block is added to the next row, and the sum of the consecutive numbers makes triangle numbers. Another interesting fact is that the sum of two adjacent triangle numbers makes a square number. With the help of this sheet, kids can have a deep understanding of triangle numbers. It is also a great tool to help kids recognize patterns and work out the corresponding rules.

Number Blocks: Additions 5 by 5

Number Blocks: Additions 5 by 5

Number Blocks: Odd and Even numbers

Number Blocks: Odd and Even numbers

Number Blocks: Additions Upto Ten

Number Blocks: Additions Upto Ten

Number Blocks: Twelve

Number Blocks: Twelve

Number Blocks: One Hundred

Number Blocks: One Hundred

Number Blocks: All About Six

Number Blocks: All About Six

Number Blocks: All About Five

Number Blocks: All About Five

Number Blocks: All About Four

Number Blocks: All About Four

All About Shapes - What is a Triangle?

All About Shapes - What is a Triangle?

Six Different Types of Triangles

Six Different Types of Triangles

Number Blocks: Multiplications 5 by 5

Number Blocks: Multiplications 5 by 5

Number Blocks: Counting to Ten

Number Blocks: Counting to Ten

Number Blocks: Number Line to 20

Number Blocks: Number Line to 20

Number Blocks: Square Numbers

Number Blocks: Square Numbers

Addition Table 10 by 10

Addition Table 10 by 10

Addition Table 9 by 9

Addition Table 9 by 9

Addition Table 12 by 12

Addition Table 12 by 12

Basic Additions within Five

Basic Additions within Five

Addition Concepts and Counting Strategy

Addition Concepts and Counting Strategy

All about the number 3

All about the number 3

Rods from One to Ten

Rods from One to Ten

Multiplication Table 12 by 12

Multiplication Table 12 by 12

Counting from one to nine one by one via incrementation

Counting from one to nine one by one via incrementation

Multiplication Table 10 by 10

Multiplication Table 10 by 10