Short Trick to find LCM of big numbers

Duration: 4 min

This video lesson is available to enrolled students.

Return to /learn/UPPSC-COMPUTER-OPERATOR-GRADE-B/reasoning/hcf-lcm/finding-lcm/asset-short-trick-to-find-lcm-of-big-numbers after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. English Comprehension: Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Reading Comprehension, Vocabulary, Idioms and Phrases, Narrative Sequencing, Critical Reasoning
  2. Reasoning and Aptitude: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Logical Sequence Of Words, Seating Arrangements, Puzzle Solving (Puzzles), Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Data Sufficiency, Selection Decision Table (Decision Making), Calendar, Clock, Cubes & Dices, Data Arrangement, Venn Diagram, Analytical Reasoning (Counting Figures Reasoning), Number System, HCF LCM, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Speed Time and Distance, Mensuration and Geometry, Arithmetic, Mixture and Alligation, Age Problems, Data Interpretation, Alphabet and Word Tests, Numerical Reasoning, Number System, Averages, Mixtures and Alligation, Percentages, Series Completion, Analogy and Classification, Patterns in Two-Dimensional Figures, Coding and Decoding, Mathematical Operations, Direction Sense, Logical Deduction and Induction, Simplification and Approximation, Assembling and Grouping of Shapes, Transformation of Shapes, Three-Dimensional Patterns and Visualization, Cubes and Dice, Algebra, Traverse Surveying, Clocks and Calendars, Order, Ranking and Sequence, Constraint Puzzles, Syllogisms and Venn Diagrams, Ratio and Proportion, Mensuration, Permutations and Combinations, Project Monitoring, Resources and Safety, Profit, Loss and Discount, Sequences and Series, Powers, Surds and Logarithms, Subject-Verb Agreement, Sentence Completion, Geometry, Probability, Trigonometry, Measurement and Quantity Take-Off, Statistics, Data Sufficiency, Blood Relations, Speed, Time and Distance, Time and Work, Data Interpretation, Sequence and Series (Series), Algebra, Permutation and Combination, Combinatorics
  3. General Awareness: Physics, Chemistry, Biology, Geography, History, Polity, Indian Economy
  4. Computer Fundamentals: Basics of COA, Number System, Number Representation, Semiconductor Memories and Programmable Logic, Timing, Hazards and Testing, Processor Organization and Instructions, Number Systems and Codes, Combinational Logic Design, Combinational Logic Circuits, Number Systems and Codes
  5. Operating System: Introduction to OS, Unix OS, Linux OS
  6. C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  7. OOPS with C++ & Java: OOPS with C++, Java
  8. Database Management System: Basics of DBMS, SQL
  9. MS Office: MS Office Applications
  10. Internet & Web Technologies: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Protocols & Services
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video, presented by Yash Jain, is a tutorial on finding the Least Common Multiple (LCM) of numbers, specifically focusing on a method for large numbers. The video begins with an introduction to the topic, using a title card and a classroom-style animation. The core of the lesson demonstrates a step-by-step algorithm for calculating the LCM. The instructor first explains the method using the numbers 12 and 18, showing how to divide them by their common prime factors (2 and 3) to reduce them to 2 and 3, and then multiply the divisors (2 x 3) and the final quotients (2 x 3) to get the LCM of 36. The method is then applied to a more complex example with four numbers: 5, 15, 20, and 30. The instructor divides all numbers by their common prime factor 5, resulting in 1, 3, 4, and 6. The LCM of these reduced numbers is found to be 12, and the final LCM is calculated as 12 x 5 = 60. The video concludes with 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 with a cartoon teacher and a live instructor, Yash Jain, in a small window. The main screen shows a green chalkboard with the title 'Least Common Common Multiple (LCM)' and the topic '7. LCM of Big Numbers'. The instructor begins the lesson by introducing the concept of LCM, which is the smallest number that is a multiple of two or more given numbers. The first example shown is 'LCM (12, 18)'. The instructor explains the method of finding the LCM by dividing the numbers by their common prime factors. The first step shown is dividing 12 and 18 by 2, resulting in 6 and 9. The instructor then divides 6 and 9 by 3, resulting in 2 and 3. The final LCM is calculated as 2 x 3 x 2 x 3 = 36.

  2. 2:00 – 4:12 02:00-04:12

    The video continues with the second example, 'LCM (5, 15, 20, 30)'. The instructor demonstrates the same method. The numbers are divided by their common prime factor, 5, resulting in 1, 3, 4, and 6. The instructor then finds the LCM of these reduced numbers. The LCM of 1, 3, 4, and 6 is calculated as 12. The final LCM of the original numbers is then found by multiplying the common divisor (5) by the LCM of the reduced numbers (12), resulting in 5 x 12 = 60. The instructor emphasizes that this method is efficient for finding the LCM of large numbers. The video ends with a 'Thanks for Watching' screen.

The video provides a clear, step-by-step tutorial on a specific algorithm for calculating the Least Common Multiple (LCM) of multiple numbers, particularly useful for large numbers. The core method involves identifying a common prime factor of all the numbers, dividing them by this factor, and then recursively finding the LCM of the resulting quotients. The final LCM is the product of the common divisor and the LCM of the reduced numbers. The lesson progresses from a simple example (12, 18) to a more complex one (5, 15, 20, 30), demonstrating the method's scalability. The visual aids, including the animated classroom and the step-by-step writing on the virtual board, effectively support the explanation of this mathematical concept.

Loading lesson…