Short Trick to Find bigger ratio out of given 2 ratios
Duration: 9 min
This video lesson is available to enrolled students.
AI Summary
An AI-generated summary of this video lecture.
This educational video lecture, presented by Yash Jain of Knowledge Gate Eduventures, focuses on the mathematical topic of 'Ratio & Proportion', specifically detailing the methods for comparing ratios. The session begins with a clear definition of a ratio as a comparison between two quantities, supported by visual diagrams illustrating parts and wholes. The core of the lesson is dedicated to solving problems that ask students to determine which of two given ratios is greater or smaller. The instructor systematically introduces and demonstrates two primary techniques for this comparison: the Least Common Multiple (LCM) method, which involves converting fractions to a common denominator, and the cross-multiplication method, a shortcut for comparing fractions without finding a common denominator. Through a series of worked examples on a digital whiteboard, the video guides students through the step-by-step calculations required to solve these problems accurately. The visual style includes colorful backgrounds and handwritten notes to keep the content engaging.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a title slide featuring the text 'RATIO & PROPORTION' next to a 3D pie chart. The instructor then displays a definition slide stating 'Ratio: a comparison of 2 quantities' with a visual of colored dots representing parts and a whole. The topic shifts to 'Comparing Ratios' with a pink background and space-themed doodles like a rocket and a planet. The instructor writes the general notation a:b and c:d on the screen to establish the variables for comparison. This section establishes the theoretical groundwork before moving to calculations. The instructor is visible in the bottom right corner throughout.
2:00 – 5:00 02:00-05:00
The first problem is introduced on a yellow background: 'Which is greater 5:12 or 3:8?'. The instructor writes the ratios as fractions 5/12 and 3/8. He first solves this using the LCM method, identifying 24 as the common denominator. He multiplies 5/12 by 2/2 to get 10/24 and 3/8 by 3/3 to get 9/24. He compares the numerators to conclude 5:12 is greater. Next, he demonstrates the cross-multiplication method, writing 5 x 8 and 12 x 3. He calculates the products as 40 and 36, writing the inequality 40 > 36 to confirm the result. This dual-method approach reinforces the concept. The instructor uses a digital pen to write the equations.
5:00 – 8:35 05:00-08:35
The instructor presents a second problem: 'Which is smaller 3:4 or 9:16?'. He applies the cross-multiplication method, calculating 3 x 16 = 48 and 4 x 9 = 36. He explains that since 48 > 36, the first ratio is larger, making 9:16 the smaller one. He also shows the LCM method by converting 3/4 to 12/16 to compare with 9/16. The final problem is 'Which is greater 9:20 or 8:13?'. He uses cross-multiplication again, computing 9 x 13 = 117 and 20 x 8 = 160. Since 160 > 117, he concludes 8:13 is greater. The video ends with a 'THANKS FOR WATCHING' slide. The instructor gestures with his hands to emphasize points.
The video provides a structured and practical guide to comparing ratios, a fundamental skill in mathematics. By starting with definitions and progressing to multiple worked examples, the instructor ensures that students grasp both the conceptual understanding and the procedural application of the topic. The inclusion of two different methods—LCM and cross-multiplication—allows students to choose the approach that suits them best, whether they prefer finding common denominators or using the faster cross-multiplication shortcut. The clear visual presentation of calculations on the screen aids in following the logical steps required to solve ratio comparison problems effectively. The consistent use of color coding and clear handwriting helps in distinguishing between different steps and values.