Ranking and Ordering Mental Maths Tricks for Class 8
Nikita Aggarwal28 May, 2026
Importance of Ranking and Ordering Mental Maths Tricks
When faced with a multi-person arrangement problem, manual counting takes too much time. Exams have strict time limits, and every second matters. Shortcuts allow you to bypass basic counting errors and jump straight to the correct answer.
These techniques allow you to process information about the left, right, top, and bottom positions simultaneously. You don’t guess, you apply structured logic to determine exactly where someone belongs. The development of these mental strategies builds a great foundation for higher-level analytical thinking.
At the Class 8 level, comparison questions generally focus on linear arrangements or attribute-based scaling, such as comparing heights, weights, or marks. These problems require you to arrange data systematically based on specific clues.
Most problems provide partial data about a group of people. Your job is to find either the total number of individuals or the position of a specific person from the opposite end. Recognising the core structure of the question is the first step toward a quick solution.
Formulas for Ranking and Ordering Mental Maths Tricks
To solve position-based problems that grade 8 students frequently encounter, you only need to master a couple of core arithmetic formulas. The most fundamental formula connects the total number of people in a line to an individual's position from both ends.
Before using the data, ensure you identify whether the positions are given from the left and right or from the top and bottom. The logic remains identical for both scenarios.
The Total Number Formula
When you know the position of a single person from both ends of a row, use this formula to find the total number of people:
Total Number=(Position from Left+Position from Right)−1
We subtract 1 at the end because the specific person is counted twice—once from the left and once from the right.
Example:
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Rahul is 12th from the left.
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Rahul is 26th from the right.
Total students:
12+26−1=3712 + 26 - 1 = 3712+26−1=37
So, there are 37 students in the class.
For a school article, you can also write it simply as:
Total Number = Position from Left + Position from Right − 1
We subtract 1 because the person whose position is given from both sides gets counted twice.
Read More - Exponents Shortcut Methods for Class 8
Finding an Individual Position
If you already know the total number of people and a person's rank from one side, you can find their position from the opposite side using this variation:
Position from Opposite Side = (Total Number − Given Position) + 1
For example:
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Total students = 45
-
Amit is 19th from the right
Position from the left:
(45 − 19) + 1 = 27
So Amit is 27th from the left.
Ranking and Ordering Mental Maths Tricks for Ranking Order Reasoning Questions
Let us apply these formulas to common ranking order reasoning questions to see how they work in practice. Walking through real examples is the best way to understand the mechanics of the formulas.
Example 1: Finding the Total Number
Question: In a class, Rahul ranks 12th from the top and 26th from the bottom. How many students are there in the class?
To solve this quickly, add the two given ranks together and then subtract one to remove the double count.
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Top Rank: 12
-
Bottom Rank: 26
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Calculation: ₹(12 + 26) - 1 = 38 - 1 = 37₹
There are exactly 37 students in the class.
Example 2: Finding a Missing Rank
Question: A total of 45 students are sitting in a straight row facing north. If Amit is 19th from the right end, what is his position from the left end?
For this problem, subtract the known position from the total number of students, and then add one to find the correct spot.
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Total Students: 45
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Right Position: 19
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Calculation: ₹(45 - 19) + 1 = 26 + 1 = 27₹
Amit is sitting in the 27th position from the left end.
Read More - Mensuration Tricks Using Mental Maths for Class 8
Ranking and Ordering Mental Maths Tricks for Mental Ability Comparison Questions
Not all ranking questions involve literal lines of people. Many problems ask you to arrange individuals based on variable quantities like test marks, ages, heights, or weights.
Using simple inequality signs represents a great way to handle mental ability comparison tricks without getting tangled up in paragraphs of text. Always convert the text clues into clean visual equations immediately.
The following table outlines how to translate word clues into clear mathematical symbols for quick ordering:
|
Word Clue in Question |
Mathematical Translation |
Visual Meaning |
|
A is taller than B |
₹A > B₹ |
A is placed above B |
|
C is heavier than D but lighter than E |
₹E > C > D₹ |
C sits directly between E and D |
|
F is not the shortest |
₹F \neq \text{Bottom}₹ F cannot be at the very end |
|
|
G is just older than H |
₹G \rightarrow H₹ |
G and H form an unbreakable pair |
Ranking and Ordering Mental Maths Tricks for Arrangement and Sequencing Exercises
More complex exam papers introduce problems where two people swap their seats. These arrangements and sequencing exercises can look intimidating, but they follow a highly predictable pattern.
When two people interchange their positions, the total number of seats in the row stays exactly the same. You can use the new position of one person alongside the old position of the second person to crack the puzzle.
When Person A and Person B swap places, look at how many steps Person A moved from their original position. Person B must move by that exact same number of steps in the same direction.
Alternatively, you can find the total number of people in the row by adding Person A's new position to Person B's initial position from the opposite side, then subtracting one. Once you have the total, finding any other missing rank becomes simple.
Ranking and Ordering Mental Maths Tricks Practice Questions for Class 8
Reviewing various question types helps lock these mental shortcuts into your memory. The table below summarises common problem setups along with the specific mental path required to solve them.
|
Problem Type |
Given Information |
Required Output |
Quick Mental Path |
|
Simple Row |
Ranks from both ends |
Total count |
Add both ranks together, then subtract 1 |
|
Single Rank Shift |
Total count and one rank |
Opposite rank |
Subtract rank from total, then add 1 |
|
Midpoint Finding |
Two ranks from same end |
Persons in between |
Subtract smaller rank from larger, then subtract 1 |
|
Overlapping Row |
Ranks from ends and middle count |
Minimum total |
Add ranks, subtract middle count, subtract 2 |
Tips to Improve Speed Using Ranking and Ordering Mental Maths Tricks
Knowing the formulas is a good start, but building raw speed requires intentional practice. Avoid drawing long diagrams during a test, as sketches waste valuable time and increase your chances of miscounting.
Try to solve the arithmetic mentally by breaking numbers down into smaller components. For instance, if you need to calculate 45 minus 19, subtract 20 first to get 25, and then add 1 back to get 26. This mental agility prevents simple calculation errors under exam pressure.
How to Learn Ranking and Ordering Mental Maths Tricks with CuriousJr
Building strong mental math habits early gives you a massive advantage in higher classes. While ranking and ordering mental maths tricks help you ace competitive logic tests, mastering your core school textbook syllabus is just as crucial for overall academic excellence.
Exploring structured learning resources tailored specifically for your school curriculum can make your daily studies much easier. If you want to strengthen your school maths foundation, check out interactive online modules available on the CuriousJr Class 8 Learning Hub.
These resources break down complex topics into clear, easy-to-understand segments that help you secure top marks in your school exams. Join CuriousJr online Mental Maths Classes now.
