Find Square Root of Any Number in Just 5 Seconds

Duration: 9 min

This video lesson is available to enrolled students.

Return to /learn/RSSB-BASIC-COMPUTER-INSTRUCTOR/paper-1-basic-numeracy/speed-mathematics-and-basic-mathematics/speed-maths/asset-find-square-root-of-any-number-in-just-5-seconds after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About the Course: About the Course
  2. Paper-1 & 2 | Basic Numeracy: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Percentage, Average, Mensuration and Geometry, Age Problems, Arithmetic, Statistics, Probability, Profit and Loss, Simple Interest and Compound Interest, Partnership, Speed Mathematics and Basic Mathematics, Algebra, Powers and Exponents (Surds and Indices), Time and Work, Pipe and Cistern, RSSB Specific Videos - Basic Numeracy
  3. Paper-1 & 2 | Data Interpretation: Data Interpretation
  4. Paper-1 & 2 | General Mental Ability: Mental Ability, RSSB Specific Videos - Mental Ability
  5. Paper-1 & 2 | Logical Reasoning and Analytical Ability: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Analogy, Ranking, Order and Sequence, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Data Arrangement, Logical Sequence Of Words, Crypt Arithmetic
  6. Paper-1 & 2 | Decision Making and Problem Solving: Selection Decision Table (Decision Making)
  7. Paper-1 | General Science: Physics, Biology, Chemistry, RSSB Specific Videos
  8. Paper-1 | General Awareness: State Wise GK, GK- Current Affairs
  9. Paper - 2 | Digital Logic Systems: Digital Systems & Boolean Basics, Logic Gates & Hardware, Combinational Circuit, Sequential Circuits
  10. Paper-2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Calculus, Relational Algebra, SQL, NoSQL
  11. Paper-2 | Data Structures & Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Algorithm Analysis, Sorting Algorithms, Intro to Compilers, Hashing
  12. Paper 2 | Data Communication and Network Security: Introduction to CN, Data Communication, Data Link Layer - Ethernet, DLL: Error Control, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Application Layer, Hardware basics, Network Security, Ethical Hacking
  13. Paper-2 | Operating Systems: Introduction to OS, Process Management, Memory Management, File Management, Deadlock
  14. Paper-2 | Computer Organization and Architecture: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Programming the Basic Computer, Number System, Number Representation
  15. Paper 2 | System Analysis and Design: Fundamentals of Systems and Information Systems, Fundamentals of Software Engineering, SDLC and Development Approaches, Software Documentation and Software Requirements Specification (SRS), SDD and Quality Assurance, Security, Risk Management & Maintenance, Software Testing
  16. Paper-2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  17. Paper 2 | OOPS , C++ , JAVA: Language Design, OOPS with C++, Java, .Net Programming, Java Fundamentals
  18. Paper 2 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  19. Emerging Trends and AI: Emerging Tech Trends, Artificial Intelligence
  20. Paper-2 | Data Processing (Ms-Office): MS Office Applications
  21. Paper-2 | Internet and Web Technologies: HTML Basics, CSS, XML, JavaScript-Basics, Internet Fundamentals, Protocols & Services, Web Publishing & Hosting, Server Side & Security, Emerging Technologies, Terms & Abbreviations, Cyber Threats and Malware Attacks, Role of Internet and Web Services, Security in Mobile and Wireless Computing, साइबर सुरक्षा / Cyber Safety and Security, कंप्यूटर नेटवर्क / Computer Networks
  22. Paper 2 | Pedagogy: Child Development, Theories, Concept of Pedagogy, Inclusive Education, Experiential Pedagogy, Assessment & Evaluation, Psychology, Curriculum Framework & Reforms, National Education Policy (NEP) 2020
  23. Live Classes: RSSB Live Sessions
  24. Paper 1 - Full Mock Tests:
  25. Paper 2 - Full Mock Tests:
  26. BCI Previous Year Papers:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video, titled 'Speed Maths', teaches a shortcut method for estimating the square root of a number. The instructor, Yash Jain Sir, begins by introducing the topic and then presents a table of squares from 1 to 10. The core of the lesson is a rule for determining if a number is a perfect square based on its unit digit: if the unit digit is 2, 3, 7, or 8, it cannot be a perfect square; if it is 0, 1, 4, 5, 6, or 9, it may be. The method then uses a memorization table to find the possible unit digits of the square root. The instructor demonstrates this by solving for the square roots of 784, 7569, and 15625, showing how to narrow down the answer to two possibilities and then use the 'fingers' method to determine the correct one. The video concludes with a promotional message for a placement preparation course.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card reading 'SPEED MATHS' against a blue, digital background. It then transitions to a presentation slide with a space-themed background featuring planets, rockets, and stars. The main title on the slide is 'MATHEMATICS CALCULATION ON FINGER TIPS'. In the bottom right corner, the instructor, Yash Jain Sir, is visible in a small window. He introduces the topic of the video, which is a trick for calculating square roots quickly. The slide also identifies him as a 'KNOWLEDGE GATE EDUCATOR'.

  2. 2:00 – 5:00 02:00-05:00

    The video transitions to a new slide titled 'TRICK-1' and 'SQUARE ROOT OF ANY NUMBER'. The instructor begins by showing a table of squares from 1 to 10. He then explains a rule for perfect squares based on the unit digit. A slide titled 'PERFECT SQUARE' appears, stating: 'If a number has 2,3,7,8 as its unit digit then it's not a perfect square.' and 'If a number has 0,1,4,5,6,9 as its unit digit then it MAY be a perfect square.' The instructor demonstrates this by writing the number 784 and noting its unit digit is 4, which means it could be a perfect square. He then uses the table to show that the unit digit of the square root must be either 2 or 8, as 2²=4 and 8²=64.

  3. 5:00 – 9:27 05:00-09:27

    The instructor presents a 'MEMORISE THIS' table that correlates the unit digit of a number to the possible unit digits of its square root. For example, if the unit digit of the question is 4, the answer could be 2 or 8. He then applies this to the number 784, writing the square root symbol and the number. He draws a tree diagram to show the two possibilities: 2 and 8. He then demonstrates the 'fingers' method to determine the correct answer. For 784, he mentally divides the number into 7 and 84. He knows that 2²=4 and 3²=9, so the tens digit must be 2. He concludes the square root is 28. He repeats this process for 7569 and 15625, showing the same method. The video ends with a promotional slide for 'PLACEMENT PREPARATION' and a 'THANKS FOR WATCHING' screen.

The video presents a structured, step-by-step method for quickly estimating the square root of a number. It begins by establishing a foundational rule based on the unit digit of a number to determine if it can be a perfect square. This is followed by a memorization table that links the unit digit of a number to the possible unit digits of its square root. The core of the method, the 'fingers' technique, combines this knowledge with a simple division of the number to find the tens digit, allowing the user to narrow down the answer to two possibilities and then select the correct one. The lesson is taught with clear examples and visual aids, making it accessible for students looking to improve their mental math skills.

Loading lesson…