Short Tricks to calculate HCF of Decimals & Fractions

Duration: 11 min

This video lesson is available to enrolled students.

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Inside: a video lesson and guided study material.

Module outline

  1. About the Course: About the Course
  2. Paper-1 & 2 | Basic Numeracy: अनुपात और समानुपात / Ratio and Proportion, Divisibility Rules, मिश्रण और एलिगेशन / Mixture and Alligation, Permutation and Combination, Logarithm, संख्या पद्धति / Number System, महत्तम समापवर्तक और लघुत्तम समापवर्त्य / HCF and LCM, Sequence and Series (Series), समय, चाल और दूरी / Time, Speed and Distance, प्रतिशत / Percentage, औसत / Average, घन क्षेत्रमिति / Solid Mensuration, Age Problems, Arithmetic, Statistics, Probability, लाभ, हानि और बट्टा / Profit, Loss and Discount, साधारण और चक्रवृद्धि ब्याज / Simple and Compound Interest, Partnership, Speed Mathematics and Basic Mathematics, Algebra, सरलीकरण, घातांक और करणी / Simplification, Indices and Surds, समय और कार्य / Time and Work, Pipe and Cistern, RSSB Specific Videos - Basic Numeracy, समुच्चय, संबंध, फलन और विविक्त गणित / Sets, Relations, Functions and Discrete Mathematics, संख्या पद्धति और संख्या सिद्धांत / Number Systems and Number Theory, निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति / Coordinate Geometry, Vectors and 3D Geometry, बहुपद, समीकरण और सम्मिश्र संख्याएँ / Polynomials, Equations and Complex Numbers
  3. Paper-1 & 2 | Data Interpretation: आँकड़ा निर्वचन / 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: श्रेणी / Series, कूट लेखन एवं कूट वाचन / Coding-Decoding, Data Sufficiency, अशाब्दिक तर्क / Non-Verbal Reasoning, Syllogisms, बैठक व्यवस्था एवं पहेलियाँ / Seating Arrangement and Puzzles, रक्त संबंध / Blood Relations, दिशा एवं दूरी / Direction and Distance, Analytical Reasoning (Counting Figures Reasoning), गणितीय संक्रियाएँ एवं लुप्त संख्या / Mathematical Operations and Missing Numbers, कैलेंडर एवं घड़ी / Calendar and Clock, Clock, घन, पासा एवं आकृतियों की गिनती / Cubes, Dice and Figure Counting, वेन आरेख, न्याय वाक्य एवं असमानता / Venn Diagrams, Syllogism and Inequalities, सादृश्यता एवं वर्गीकरण / Analogy and Classification, क्रम एवं रैंकिंग / Order and Ranking, कथन आधारित तार्किक विवेचन / Statement-Based Reasoning, Data Arrangement, वर्णमाला एवं संख्या परीक्षण / Alphabet and Number Test, Crypt Arithmetic
  6. Paper-1 & 2 | Decision Making and Problem Solving: आँकड़ों की पर्याप्तता एवं निर्णय क्षमता / Data Sufficiency and Decision Making
  7. Paper-1 | General Science: वैज्ञानिक उपलब्धियाँ और अनुसंधान / Scientific Achievements and Research, Biology, Chemistry, RSSB Specific Videos
  8. Paper-1 | General Awareness: राज्य विशेष सामान्य ज्ञान / State-Specific General Knowledge, समसामयिकी / Current Affairs
  9. Paper-2 | Fundamentals of Computer: Basics of COA, Number System, Floating Point Rep, Number Representation
  10. Paper - 2 | Digital Logic Systems: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits
  11. Paper-2 | Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Linux OS, Distributed Systems
  12. Paper-2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, Relational Calculus, File Organization & Indexing, Transaction Management, Concurrency Control
  13. Paper-2 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  14. Paper-2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  15. Paper 2 | Oops, C++, Java: Language Design, OOPS with C++, Java, .Net Programming, Java Fundamentals
  16. 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
  17. Paper 2 | Emerging Trends and AI: Emerging Tech Trends, कंप्यूटर के मूल सिद्धांत / Computer Fundamentals, व्यापार, विपणन एवं उपभोक्ता संरक्षण / Trade, Marketing and Consumer Protection, कंप्यूटर नेटवर्क / Computer Networks
  18. Paper-2 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Advanced Algorithms
  19. Paper 2 | Data Communication and Network Security: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security, Ethical Hacking
  20. Paper-2 I Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  21. Paper-2 | Computer Organization and Architecture: Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations
  22. Paper-2 | Web Development: JavaScript-Basics, HTML Basics, CSS, XML
  23. Pedagogy: वृद्धि और विकास / Growth and Development, Concept of Pedagogy, संज्ञानात्मक प्रक्रियाएँ / Cognitive Processes, विकास के सिद्धांत / Theories of Development, समावेशी शिक्षा / Inclusive Education, Experiential Pedagogy, समाजीकरण और जेंडर / Socialisation and Gender, National Education Policy (NEP) 2020
  24. Live Sessions: RSSB Live Sessions
  25. RSSB Paper 1 - Full Mock Tests:
  26. RSSB Paper 2 - Full Mock Tests:
  27. SCI Previous Year Papers:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video, presented by Yash Jain from Knowledge Gate Eduventures, provides a comprehensive tutorial on finding the Highest Common Factor (HCF) of decimal numbers. The lecture begins with an introduction to the topic, followed by a detailed explanation of the method. The core technique involves converting decimal numbers into whole numbers by multiplying them by a power of 10 (e.g., 10, 100, 1000) to eliminate the decimal point. The HCF of these resulting whole numbers is then calculated using the prime factorization method. Finally, the result is converted back to a decimal by dividing by the same power of 10 used in the initial step. The video demonstrates this process with two examples: first, HCF(0.15, 2.5, 10), which is solved by multiplying by 100 to get HCF(15, 250, 1000), yielding 5, and then dividing by 100 to get 0.05. Second, HCF(2.4, 0.84, 0.108) is solved by multiplying by 1000 to get HCF(2400, 840, 108), yielding 12, and then dividing by 1000 to get 0.012. The video concludes with a summary of the concept and a 'Thanks for Watching' screen.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card displaying 'LCM & HCF' against a digital background. It then transitions to a classroom setting where a female cartoon teacher stands beside a green chalkboard. The board displays the title 'HCF' and the word 'And' with a small boy character. The instructor, Yash Jain, is visible in a small window. The scene sets the stage for a lesson on the Highest Common Factor, with the title 'Highest Common Factor (HCF)' clearly written on the board.

  2. 2:00 – 5:00 02:00-05:00

    The video presents the first example: HCF(0.15, 2.5, 10). The instructor explains the method of converting decimals to whole numbers. The on-screen text shows the numbers being multiplied by 100: 0.15 x 100 = 15, 2.5 x 100 = 250, and 10 x 100 = 1000. The problem is thus transformed into finding the HCF of the whole numbers 15, 250, and 1000. The instructor then begins the prime factorization process, writing the numbers and dividing them by common prime factors like 5.

  3. 5:00 – 10:00 05:00-10:00

    The instructor completes the prime factorization for the first example, showing that the HCF of 15, 250, and 1000 is 5. The final step is to convert this result back to a decimal by dividing by 100, resulting in 0.05. The video then moves to the second example, HCF(2.4, 0.84, 0.108). The instructor demonstrates the conversion by multiplying each number by 1000: 2.4 x 1000 = 2400, 0.84 x 1000 = 840, and 0.108 x 1000 = 108. The problem is now HCF(2400, 840, 108). The instructor proceeds to find the HCF of these three numbers using prime factorization, dividing by common factors like 2 and 3, and arrives at the result 12. The final answer is obtained by dividing 12 by 1000, giving 0.012.

  4. 10:00 – 10:56 10:00-10:56

    The video concludes with a summary of the concept. The instructor reiterates the formula: HCF of decimals = HCF of the numerators / LCM of the denominators, after converting the decimals to fractions. The final answer for the second example, 0.012, is confirmed. The video ends with a black screen displaying the text 'THANKS FOR WATCHING' in an orange and white box.

The video provides a clear, step-by-step guide on calculating the HCF of decimal numbers. The central idea is to transform the problem into one involving whole numbers, which is a standard and effective method. The instructor uses two distinct examples to illustrate the process, ensuring the concept is well-understood. The key takeaway is the systematic approach: convert decimals to whole numbers by multiplying by a power of 10, find the HCF of the whole numbers, and then divide the result by the same power of 10 to get the final decimal answer. This method is reliable and avoids the complexity of dealing with decimals directly in factorization.

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