Demo: What is the purpose of Divisibility Rules

Duration: 8 min

This video lesson is available to enrolled students.

Return to /learn/ZERO-TO-HERO/aptitude/divisibility-rules/basic-concepts-of-divisibility/asset-demo-what-is-the-purpose-of-divisibility-rules after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control
  2. Discrete Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic
  3. Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  4. Computer Architecture: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design
  5. Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Virtual Memory, Disc Scheduling, File Management, Memory Management, Threads & Process Creation
  6. Computer Networks: Introduction to CN, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Network Security, Hardware Basics
  7. Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  8. Algorithms: Algorithm Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Time Complexity Analysis
  9. Theory Of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory
  10. Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
  11. C language: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums
  12. Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  13. Emerging Trends & AI: Emerging Tech Trends, Artificial Intelligence, Cloud Computing
  14. Computer Graphics: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing
  15. Aptitude: Percentage, Ratio and Proportion (Ratios), Logarithm, HCF LCM, Divisibility Rules, Average, Sequence and Series (Series), Number System, Powers and Exponents (Surds and Indices), Algebra, Permutation and Combination, Probability, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Pipe and Cistern, Speed Time and Distance, Mixture and Alligation, Mensuration and Geometry, Mental Ability, Age Problems, Partnership, Statistics, Data Interpretation, Arithmetic, Speed Mathematics and Basic Mathematics, TCS NQT Advanced Quantitative Ability, Gamified / Game Based Aptitude, Linear Algebra, Trigonometry
  16. Reasoning: Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Selection Decision Table (Decision Making), Logical Sequence Of Words, Crypt Arithmetic, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence, TCS NQT Advanced Reasoning Ability
  17. English (Verbal Ability): Vocabulary, Noun, Pronoun, Adjectives, Preposition, Articles, Direct and Indirect Speech, Tenses, Conjunction, Subject Verb Agreement (Verb Noun Agreement), Modals, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Sentence Construction, Active Passive Voice (Voice), Determiner, Facts, Inference and Judgements, Adverb, Interjection, Verb, English Writing Ability
  18. Engineering Mathematics: Calculus, Vectors
  19. GATE Live Class Recordings 2026: GATE 2026 Live Class
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video introduces the concept of divisibility rules as mathematical shortcuts for determining if one number can be exactly divided by another without performing long division. The lesson begins by defining divisibility as a process where the result of dividing one number by another must be a whole number. The instructor uses visual aids, including a colorful circular chart and handwritten calculations, to illustrate rules for integers 2 through 10. Key examples include testing numbers like 723 against the rule for 3 by summing digits (7+2+3=12) and checking if the sum is divisible by 3. The video emphasizes that zero is divisible by any number except itself, and clarifies that 'divisible by' is synonymous with 'can be exactly divided by'.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a colorful educational chart titled 'Divisibility Rules' that organizes shortcuts for integers 2 through 10. The instructor uses a green pointer to highlight specific sections, such as the rule for number 2 which requires numbers to end in even digits (0, 2, 4, 6, 8). Visual cues include text like 'ends in 0' for divisibility by 10 and instructions to sum digits for rules like 3 and 9. The chart displays examples such as '524' and '6534' to demonstrate application. The instructor circles key terms on the screen, such as 'sum of the digits is ÷ by 3', to guide student focus toward the core mechanics of each rule.

  2. 2:00 – 5:00 02:00-05:00

    The lesson transitions to a fundamental definition of divisibility, stating that 'Divisible By' means when you divide one number by another the result is a whole number. The instructor writes handwritten calculations on the right side of the screen to contrast divisible and non-divisible cases. For instance, '14 is divisible by 7' because 14 ÷ 7 = 2 exactly, whereas '15 is not divisible by 7' because the result is a fraction (2 1/7). Red circles are used to emphasize critical terms like 'whole number' and 'exactly'. The instructor also notes that 0 is divisible by 7 because 0 ÷ 7 = 0 exactly, reinforcing that zero counts as a whole number in this context.

  3. 5:00 – 8:19 05:00-08:19

    The final segment explains the practical purpose of divisibility rules as a method to test numbers without extensive calculation. The instructor demonstrates the rule for 3 using the example of 723, showing that summing its digits (7+2+3=12) and checking if 12 is divisible by 3 confirms the answer. The screen displays text stating 'We could try dividing 723 by 3' or use the rule. The lesson concludes with a note that zero is divisible by any number except itself, illustrated with fraction examples. The video ends with a 'THANKS FOR WATCHING' message after summarizing the efficiency of these rules over standard division.

The video effectively structures the learning progression from visual recognition of rules to conceptual understanding and finally practical application. The initial use of a circular chart serves as an anchor for memorization, allowing students to quickly identify patterns like even endings or digit sums. The middle section grounds these shortcuts in mathematical theory by defining divisibility through exact division and whole number results, using 14/7 versus 15/7 to create a clear cognitive contrast. The final application with 723 demonstrates the utility of the rules, showing how they bypass long division. A critical nuance highlighted is the status of zero, which is divisible by any non-zero number, a detail often overlooked in basic arithmetic. The consistent use of visual cues like red circles and handwritten notes ensures that key definitions remain the focal point throughout the lesson.

Loading lesson…