Introduction
In this topic, students must find the odd term in a given series. One number or word does not follow the pattern. It is similar to finding the odd one out, but here more terms are given. Understanding the pattern helps identify the incorrect term easily.
Explanation Step by Step

A number series follows a rule such as addition, subtraction, multiplication, or squares. Each term follows that rule. If one term breaks the pattern, it is the odd term. Students should carefully check the relationship between all numbers.
Sub-topics
Series - To find the odd term
Each series follows a logical pattern. The goal is to identify the term that does not fit the pattern.
Examples
Example 1
Tricks and Shortcuts
Check differences first. Then check multiplication or square patterns. Observe quickly.
Common Mistakes
Students rush and miss checking all terms carefully. They assume patterns too quickly.
Practice Questions
Easy Questions
- 2, 4, 6, 8, 11, 12
- 5, 10, 15, 21, 25
- 3, 9, 27, 81, 100
Medium Questions
- 1, 3, 6, 10, 15, 21, 28, 30
- 4, 9, 16, 25, 30, 49
- 7, 14, 28, 56, 100
Hard Questions
- 2, 6, 12, 20, 30, 42, 50
- 11, 13, 17, 19, 21, 23
- 3, 5, 9, 17, 33, 60
Revision Summary
Understand the pattern in the series. Identify the term that breaks the rule. Practice improves speed and accuracy.