NCERT - 8 - Maths :: Direct and Inverse Proportion
Go To: NCERT-Mathematics-Grade 8
Course Content / Subtopic list:
- Direct Proportion
- Inverse Proportion
[Author - Kripa S]
http://epathshala.nic.in/wp-content/doc/book/flipbook/ClassVIIIFlipbook/0853-Ganit/Chapter_13/index.html (NCERT Hindi Medium)
http://epathshala.nic.in/wp-content/doc/book/flipbook/ClassVIIIFlipbook/0852-Mathematics/13/index.html (NCERT English Medium)
https://drive.google.com/open?id=0BzNF2YyqQxJ-TjdJSWgyZk1QVmM (JEPC Board) (Hindi Medium)
Lesson Plan
[Author - Kripa S]
Objective: Revise ratio, proportion and learn direct and inverse proportion
Subtopics to be covered:
- Ratio and proportion concept
- Direct proportion with examples
- Inverse proportion with examples
Subtopics to be covered:
- Students can solve problems on direct and inverse proportion
Videos
[Author - Rishi Mazumdar]
https://hi.khanacademy.org/math/in-math-by-grade/in-eighth-grade-math/direct-inverse-proportions (Khan Academy)
Images
[Author - Kripa S]
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTHyX4m1veFeiPuZymoJGrmR8_G1Hi8qZKBzfUE66geuwYD0ry0 (proportion example 1)
https://image.pbs.org/poster_images/assets/PROPORTION.jpg.resize.710x399.jpg (proportion example 2)
https://www.mathsisfun.com/algebra/images/proportion-1a.gif (proportion with numbers)
https://www.mathsisfun.com/algebra/images/proportion-inverse-square.svg (inverse proportion)
Activities
[Author - Kripa S]
1. One pen costs 5 rs. How much with 10 pens cost? Is this direct proportion or inverse proportion? Why?
2. In 1 day, my sister reads 20 pages of a book. In how many days can she finish a book of 200 pages? If my sister reads 25 pages in a day, in how many days can she finish the book? Is this direct proportion or inverse proportion? Why?
Transliteration
[Contributor - Suwetha]
Term | Transliterated Term | Translated Term |
natural number | नेचुरल नंबर | प्राकृत संख्याएँ |
direct proportions | डायरेक्ट प्रोपोरशंस | सीधा समानुपात |
inverse proportions | इनवर्स प्रोपोरशंस | प्रतिलोम समानुपात |
ratio | रेश्यो | अनुपात |
increase | इनक्रीस | वृद्धि |
decrease | डिक्रीसे | कमी |
constant | कांस्टेंट | अचर |
direct variation | डायरेक्ट वेरिएशन | विचरण |
unitary method | यूनिटरी मेथड | ऐकिक विधि |
vary directly | वेरी डायरेक्टली | परस्पर अनुक्रमानुपाती |
vary inversely | वेरी इनवेरसेली | परस्पर व्युत्क्रमानुपाती |
quantities | क्वान्टीटीएस | राशियों |
positive number | पॉजिटिव नंबर | राशियाँ |
product | प्रोडक्ट | गुणनफल |
variables | वेरिएबल्स | चर |





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