Divisibility Rules of 28, 29, 30 and 31
Duration: 10 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- Child Development and Pedagogy: Concept of Pedagogy, Psychology, Child Development, Theories, Personality Development, Individual Differences, Learning and Motivation, Understanding Diverse Learners, Inclusive Education, Mental Health & Life Skills, Teaching-Learning Process, Teaching Methods & Strategies, Experiential Pedagogy, Assessment & Evaluation, National Education Policy (NEP) 2020, Curriculum Framework & Reforms, Miscellaneous Topics, Learners & Learning Process, Factors Affecting Teaching, Methods of Teaching, Classroom Management & Communication, Teaching-Learning Aids & ICT Integration, Curriculum & School Environment, Evaluation, Assessment & Measurement, Inclusive Education & Special Needs
- Mathematics: Number System & Place Value, Whole Numbers & Four Operations, Factors, Multiples, Divisibility, HCF & LCM, Fractions & Decimals, Patterns, Ratio, Proportion & Percentage, Measurement — Length, Mass, Capacity, Time, Money, Geometry — Shapes, Lines & Angles, Symmetry, Spatial Understanding, Mensuration — Perimeter, Area, Surface Area, Volume, Data Handling, Graphs & Probability, Mathematics Pedagogy
- Environmental Studies: Family & Friends, Relationships, Community, Food & Nutrition, Health & Hygiene, Shelter & Houses, Water (sources, conservation), Travel, Transport & Communication, Things We Make & Do (materials, occupations, crafts), Plants (types, parts, uses), Animals (habitats, features, care), Our Body & Senses, Air, Weather, Sky & Seasons, Maps, Directions & Local Environment, Festivals, Culture & Heritage (India), Environment Conservation, Waste & Pollution, Natural Disasters & Safety, EVS Pedagogy
- Language I/II — Hindi: वर्ण-विचार (भाषा, लिपि और वर्णमाला), वर्तनी और वर्ण-विन्यास, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, विशेषण और क्रिया, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, शब्द-भंडार, सामान्य अशुद्धियाँ (Samanya Ashuddhiyaan), अनेक शब्दों के लिए एक शब्द, मुहावरे और लोकोक्तियाँ, अपठित गद्यांश और अपठित पद्यांश, Multi-Topic Content (Cross-Concept Material), वर्णमाला (Varnmala), वाक्य-शुद्धि, अशुद्धि शोधन और विराम चिह्न, उपसर्ग और प्रत्यय, तत्सम, तद्भव, देशज और विदेशी शब्द, अनेकार्थी और शब्द-युग्म, अलंकार, रस और छंद, शब्दोत्पत्ति एवं भाषा-बोलियाँ, वाक्य-पूर्ति और अनुच्छेद-रचना
- Language I/II — English: Noun, Pronoun, Determiner, Articles, Adjectives, Verb, Adverb, Preposition, Conjunction, Interjection, Sentence Structure, Phrases & Clauses, Tenses, Subject Verb Agreement (Verb Noun Agreement), Modals, Active Passive Voice (Voice), Direct and Indirect Speech, Vocabulary, Sentence Construction, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing)
- Language I/II — Sanskrit: वर्ण, उच्चारण, सन्धि, शब्दरूप, धातुरूप, कारक-विभक्ति, समास, प्रत्यय, उपसर्ग, वाच्य, सङ्ख्या, अव्यय, अपठित अवबोधन
- Language I/II — Urdu: Spelling & Diacritics, Vocabulary, Grammar (اسم, فعل, صفت, ضمیر), Idioms & Proverbs, Comprehension
- Language I/II — Bengali: Grammar, Vocabulary, Idioms & Expressions, Writing & Composition, Comprehension
- Language Pedagogy (Language I and II): Language Pedagogy (Hindi/English/Sanskrit/Urdu learning & teaching)
- Mathematics (Video Lessons & Notes): Number System, Arithmetic, Divisibility Rules, HCF LCM, Speed Mathematics and Basic Mathematics, Mensuration and Geometry, Statistics, Mental Ability
- Environmental Studies (Video Lessons & Notes): Environment, Ecosystem, Biomes & Environmental Issues, Air Pollution, Water Pollution, Soil, Noise Pollution and Waste Management, Natural Resources, Energy & Disaster Management, Global Environmental Conventions – COP, Protocols & ISA, MDG & SDG
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This educational video presents a series of divisibility rules for the numbers 28, 29, 30, and 31, taught by an instructor named Yash Jain Sir. The video begins with a title card and a colorful, hand-drawn diagram illustrating various divisibility rules. The main content consists of four distinct slides, each dedicated to a specific number. For 28, the rule is that a number is divisible by 28 if it is divisible by both 4 and 7, with the example of 140 being used. For 29, the rule is to add three times the last digit to the remaining leading truncated number, and if the result is divisible by 29, then so is the original number, demonstrated with the example 15689. For 30, the rule is that a number must be divisible by both 3 and 10, illustrated with the example 270. Finally, for 31, the rule is to subtract three times the last digit from the remaining leading truncated number, with the example 7998 being shown. The video concludes with a 'Thanks for Watching' screen.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a title card displaying 'DIVISIBILITY RULES' over a background of scattered numbers. This transitions to a colorful, hand-drawn diagram titled 'DIVISIBILITY RULES' which visually explains rules for numbers 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11. The instructor, Yash Jain Sir, appears in a small window in the bottom right corner. The first main slide is then shown, titled 'Divisibility Rule of 28'. It states that a number is divisible by 28 if it is divisible by 4 and by 7, with the example 140. The instructor begins to explain the rule, and the number 28 is written as 4 x 7 on the slide.
2:00 – 5:00 02:00-05:00
The video continues to focus on the 'Divisibility Rule of 28'. The instructor explains that since 28 = 4 x 7, a number must be divisible by both 4 and 7. He demonstrates this with the example 140. He shows that 140 divided by 4 is 35, and 140 divided by 7 is 20. He also writes the multiplication 28 x 5 = 140 to reinforce the concept. The slide remains on screen, and the instructor's voiceover explains the logic behind the rule, emphasizing that if a number is divisible by two co-prime numbers, it is divisible by their product.
5:00 – 10:00 05:00-10:00
The video transitions to a new slide titled 'Test for divisibility by 29'. The rule is stated: 'Add three times the last digit to the remaining leading truncated number. If the result is divisible by 29, then so was the first number.' An example is provided: 15689. The instructor demonstrates the process step-by-step: 1568 + 3*9 = 1568 + 27 = 1595. He continues: 159 + 3*5 = 159 + 15 = 174. Then: 17 + 3*4 = 17 + 12 = 29. Since 29 is divisible by 29, the original number 15689 is also divisible by 29. The video then moves to the 'Divisibility Rule of 30', stating it is divisible by 3 and 10, with the example 270. Finally, it presents the 'Test for divisibility by 31', which is to 'Subtract three times the last digit from the remaining leading truncated number.' The example 7998 is used: 799 - 3*8 = 799 - 24 = 775. Then: 77 - 3*5 = 77 - 15 = 62. Since 62 is 2*31, 7998 is divisible by 31.
10:00 – 10:05 10:00-10:05
The video concludes with a final screen. The background is a dark purple gradient. In the center, the text 'THANKS FOR WATCHING' is displayed in a large, white, sans-serif font. This is the end of the lecture.
The video provides a clear and structured lesson on advanced divisibility rules. It follows a consistent pattern: introducing a rule for a specific number, explaining the logic (often by breaking the number into its prime factors), and then demonstrating the rule with a detailed, step-by-step example. The use of a hand-drawn diagram at the beginning provides context, while the subsequent slides focus on one rule at a time, ensuring clarity. The progression from 28 to 31 is logical, covering a range of composite numbers and demonstrating different types of rules (multiplication, addition, subtraction). The instructor's methodical approach makes the concepts accessible for students preparing for competitive exams.