Demo: Divisibility Rules of 2, 3 and 4

Duration: 12 min

This video lesson is available to enrolled students.

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Inside: a video lesson and guided study material.

Module outline

  1. Child Development and Pedagogy / बाल विकास एवं शिक्षाशास्त्र: Concept of Development / विकास की अवधारणा, Psychological Theories of Development / विकास के मनोवैज्ञानिक सिद्धांत, Individual Differences, Personality and Gender / व्यक्तिगत भिन्नताएँ, व्यक्तित्व एवं जेंडर, Intelligence and Creativity / बुद्धि एवं सृजनात्मकता, Learning and Its Theories / अधिगम एवं इसके सिद्धांत, How Children Think and Learn / बालक कैसे सोचते एवं सीखते हैं, Emotion, Motivation, Mental Health and Guidance / संवेग, अभिप्रेरणा, मानसिक स्वास्थ्य एवं निर्देशन, Inclusive Education / समावेशी शिक्षा, Teaching-Learning Process / शिक्षण-अधिगम प्रक्रिया, Teaching Methods and Strategies / शिक्षण विधियाँ एवं रणनीतियाँ, Assessment and Evaluation / आकलन एवं मूल्यांकन, Curriculum and School Activities / पाठ्यचर्या और विद्यालयी गतिविधियाँ, Lesson Planning and Teaching Skills / पाठ योजना और शिक्षण कौशल, Teaching Resources and Educational Technology / शिक्षण संसाधन और शैक्षिक प्रौद्योगिकी, Educational Thinkers, Aims and National Policies / शैक्षिक विचारक, उद्देश्य एवं राष्ट्रीय नीतियाँ, Classroom Management and Communication / कक्षा प्रबंधन और सम्प्रेषण, Teacher Identity and Professional Development / शिक्षक पहचान और व्यावसायिक विकास, Social Science Pedagogy / सामाजिक विज्ञान शिक्षणशास्त्र, Social and Political Life / सामाजिक एवं राजनीतिक जीवन, Science Pedagogy / विज्ञान शिक्षण शास्त्र, Life Skills, Values, Peace and Environmental Education / जीवन कौशल, मूल्य, शांति एवं पर्यावरण शिक्षा, Constitution, Commissions, Acts and Schemes in Education / संविधान, आयोग, अधिनियम एवं योजनाएँ
  2. Mathematics / गणित: Number System & Place Value / संख्या पद्धति एवं स्थानीय मान, Basic Operations, Simplification & Patterns / मूलभूत संक्रियाएँ, सरलीकरण एवं पैटर्न, Factors, Divisibility, HCF & LCM / गुणनखंड, विभाज्यता, म.स.प. एवं ल.स.प., Fractions & Decimals / भिन्न एवं दशमलव, Squares, Cubes, Exponents & Surds / वर्ग, घन, घातांक एवं करणी, Measurement: Length, Mass, Capacity, Time & Money / मापन: लंबाई, भार, धारिता, समय एवं मुद्रा, Algebra / बीजगणित, Ratio, Proportion, Average & Ages / अनुपात, समानुपात, औसत एवं आयु, Percentage, Profit–Loss & Interest / प्रतिशत, लाभ-हानि एवं ब्याज, Time & Work and Speed–Distance / समय-कार्य एवं चाल-दूरी, Lines, Angles, Shapes & Coordinates / रेखाएँ, कोण, आकृतियाँ एवं निर्देशांक, Triangles, Quadrilaterals, Circles & Trigonometry / त्रिभुज, चतुर्भुज, वृत्त एवं त्रिकोणमिति, Mensuration: Perimeter, Area & Volume / क्षेत्रमिति: परिमाप, क्षेत्रफल एवं आयतन, Data Handling, Statistics & Probability / आँकड़ा प्रबंधन, सांख्यिकी एवं प्रायिकता, Mathematics Pedagogy / गणित शिक्षणशास्त्र, Alphabet & Number Test / वर्णमाला एवं संख्या परीक्षण, Non-Verbal Reasoning / अशाब्दिक तर्क, Dice & Cubes / पासा एवं घन, Mathematical Operations & Arithmetical Reasoning / गणितीय संक्रियाएँ एवं अंकगणितीय तर्क, Ranking, Seating Arrangement & Puzzles / क्रम, बैठक व्यवस्था एवं पहेली, Calendar & Clock / कैलेंडर एवं घड़ी, Venn Diagrams & Logical Deduction / वेन आरेख एवं तार्किक निगमन
  3. Environmental Studies / पर्यावरण अध्ययन: Family, Friends and Community / परिवार, मित्र और समुदाय, Plants / पौधे, Animals / जंतु, Farming and Animal Husbandry / खेती और पशुपालन, Food and Nutrition / भोजन और पोषण, Body and Health / शरीर और स्वास्थ्य, Water / जल, Shelter / आवास, Travel, Transport and Communication / यात्रा, परिवहन और संचार, Maps, Directions and India / मानचित्र, दिशाएँ और भारत, Things We Make and Do / हम क्या बनाते और करते हैं, Earth, Sky and Disasters / पृथ्वी, आकाश और आपदाएँ, Environment, Ecology and Wildlife / पर्यावरण, पारिस्थितिकी और वन्यजीव, Natural Resources, Pollution and Climate Change / प्राकृतिक संसाधन, प्रदूषण और जलवायु परिवर्तन, Pedagogy of Environmental Studies / पर्यावरण अध्ययन का शिक्षणशास्त्र, Physical Geography / भौतिक भूगोल, Resources and Development / संसाधन एवं विकास, Force, Pressure, Work and Energy / बल, दाब, कार्य एवं ऊर्जा, Environment and Ecology / पर्यावरण एवं पारिस्थितिकी, Science & Technology / विज्ञान एवं प्रौद्योगिकी, Heat and Sound / ऊष्मा एवं ध्वनि, Light / प्रकाश, Universe and Natural Phenomena / ब्रह्मांड एवं प्राकृतिक परिघटनाएँ, Chemical Reactions, Acids, Bases and Salts / रासायनिक अभिक्रियाएँ, अम्ल, क्षार एवं लवण, Natural Vegetation, Wildlife and World Regions / प्राकृतिक वनस्पति, वन्य जीवन एवं विश्व के प्रदेश, Environment & Climate Affairs / पर्यावरण एवं जलवायु समसामयिकी
  4. Language I/II — हिंदी / Hindi: भाषा, लिपि और वर्ण-विचार, संधि, शब्द-स्रोत और शब्द-रचना, समास, शब्द-भेद: विकारी और अविकारी, लिंग, वचन, कारक, काल और वाच्य, वाक्य-विचार और शुद्ध लेखन, शब्द-भंडार, रस, छंद, अलंकार और शब्द-शक्ति, हिंदी साहित्य, अपठित बोध, हिंदी शिक्षणशास्त्र
  5. Language I/II — English: Sounds, Spelling and Word Formation, Parts of Speech, Nouns and Pronouns, Articles, Determiners and Adjectives, Verbs and Modals, Tenses and Subject–Verb Agreement, Adverbs, Prepositions and Conjunctions, Sentence Structure, Voice and Narration, Vocabulary, Sentence Correction and Writing Skills, Poetry and English Literature, Reading Comprehension, Pedagogy of English Language
  6. Language I/II — संस्कृत / Sanskrit: वर्णविचारः एवं संज्ञाप्रकरणम्, सन्धिप्रकरणम्, शब्दरूपाणि, धातुरूपाणि, कारकाणि एवं विभक्तयः, उपसर्गाः एवं अव्ययानि, प्रत्ययप्रकरणम्, समासप्रकरणम्, वाच्यप्रकरणम्, संख्याज्ञानम्, शब्दज्ञानम् एवं अनुवादः, अपठितावबोधनम्, संस्कृतसाहित्यम् एवं काव्यशास्त्रम्, संस्कृतशिक्षणशास्त्रम्
  7. Language I/II — اردو / Urdu: رسم الخط، املا اور تلفظ, ذخیرۂ الفاظ, قواعد, محاورے اور ضرب الامثال, شعر و سخن, اردو ادب کی تاریخ, تفہیمِ عبارت, اردو کی تدریس
  8. Language I/II — বাংলা / Bengali: ভাষা, ধ্বনি ও বর্ণ, সন্ধি ও বানান, শব্দের উৎস ও গঠন, সমাস, পদ পরিচয়, কারক ও বিভক্তি, ক্রিয়া ও কাল, বাক্যতত্ত্ব, শব্দার্থ ও বাগর্থ, পাঠ অনুধাবন ও সাহিত্য, নির্মিতি ও পত্রলিখন, বাংলা শিক্ষণবিদ্যা
  9. Extra Practice (beyond syllabus) / अतिरिक्त अभ्यास (पाठ्यक्रम से बाहर): Computer Hardware and Peripherals / कंप्यूटर हार्डवेयर एवं परिधीय उपकरण, International Relations & Organisations / अंतरराष्ट्रीय संबंध एवं संगठन, Indian Economy: Data & Current Affairs / भारतीय अर्थव्यवस्था: आँकड़े एवं समसामयिकी
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a structured lesson on the divisibility rules for integers, specifically focusing on 1, 2, 3, and 4. The instructor begins by defining the scope of integers to exclude fractions before introducing the trivial rule that any integer is divisible by 1. The lesson progresses systematically to more complex rules, starting with divisibility by 2, which relies on the parity of the last digit. Subsequently, the rule for divisibility by 3 is explained using the sum of digits method, including a demonstration on how to repeat the process for large numbers. Finally, the video covers divisibility by 4 through two methods: checking the last two digits and a mental math shortcut involving halving the number twice. Throughout the lecture, visual aids such as checkmarks, crosses, and step-by-step calculations are used to reinforce the concepts.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with an introduction to the concept of divisibility, specifically establishing that any integer is divisible by 1. The instructor emphasizes a critical definition on the slide: 'Any integer (not a fraction) is divisible by 1,' underlining key terms to ensure students distinguish between whole numbers and fractions. To illustrate this, the instructor lists specific examples of integers such as 8, 10, 729, and 499. Visual cues include checkmarks next to valid integers and crosses or exclusions for fractions, setting a foundational understanding of the number types applicable to these rules.

  2. 2:00 – 5:00 02:00-05:00

    The lesson transitions to the divisibility rule for 2, stating that a number is divisible by 2 if its last digit is even (0, 2, 4, 6, or 8). The instructor validates this rule using the examples '128 Yes' and '129 No,' clearly marking which numbers satisfy the condition based on their final digit. The segment also introduces a seven-digit number N represented as 'abcabc,' likely to set up future problems involving patterns. The teaching method involves underlining the rule and using visual checks to confirm whether specific numbers meet the criteria, reinforcing the concept of evenness.

  3. 5:00 – 10:00 05:00-10:00

    This section covers the divisibility rule for 3, explaining that a number is divisible by 3 if the sum of its digits is divisible by 3. The instructor demonstrates this with '381 (3+8+1=12, and 12÷3 = 4) Yes' and '217 (2+1+7=10, and 10÷3 = 3 1/3) No.' For larger numbers like '99996,' the rule is applied iteratively: summing digits to get 42, then summing again to get 6. The video then introduces the rule for 4, stating 'The last 2 digits are divisible by 4,' verified with examples like '1312 is (12÷4=3) Yes' and '7019 is not (19÷4=4 3/4) No.'

  4. 10:00 – 12:07 10:00-12:07

    The final segment reinforces the divisibility rule for 4 by introducing a 'quick check' method: halving the number twice to see if the result remains a whole number. The instructor demonstrates this with '12/2 = 6, 6/2 = 3' (Yes) and '30/2 = 15, 15/2 = 7.5' (No). The video concludes by applying these methods to a larger number, '1214,' and ends with a 'Thanks for watching' screen. The visual evidence includes handwritten calculations showing the division steps and explicit text confirming the rule that 'The last 2 digits are divisible by 4.'

The lecture follows a logical progression from simple to complex divisibility rules, ensuring students build confidence with each step. The instructor consistently uses visual verification methods like checkmarks and crosses to make abstract rules concrete. Key takeaways include the strict definition of integers for divisibility by 1, the reliance on the last digit for divisibility by 2 and 4, and the iterative summing of digits for divisibility by 3. The inclusion of a 'quick check' method for divisibility by 4 adds practical value, offering students an alternative mental math strategy. The use of specific numerical examples like 381 and 99996 ensures that students can apply the rules to both small and large numbers effectively.

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