Short Trick to find LCM of decimal numbers

Duration: 7 min

This video lesson is available to enrolled students.

Enroll to watch — TCS SuperSet Course

AI Summary

An AI-generated summary of this video lecture.

This educational video, presented by Yash Jain from Knowledge Gate Eduventures, provides a comprehensive tutorial on calculating the Least Common Multiple (LCM) of decimal numbers. The lesson begins with an introduction to the topic, followed by a detailed explanation of the method. The core technique involves converting decimal numbers into whole numbers by multiplying them by a power of 10 (e.g., 10, 100) to eliminate the decimal point. The LCM of these resulting whole numbers is then calculated using prime factorization. Finally, the result is divided by the same power of 10 used in the initial conversion to obtain the LCM of the original decimals. The video demonstrates this process with two examples: first, LCM(2.8, 0.63), and second, LCM(0.18, 0.24, 0.3). The instructor uses a digital whiteboard to write out the steps, including the prime factorization of the numbers and the final calculation, ensuring a clear and logical progression of the concept.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card displaying 'LCM & HCF' against a digital, data-stream background. It then transitions to a classroom-style presentation with a cartoon teacher and a live video feed of the instructor, Yash Jain. The main topic is introduced on a green chalkboard: 'Least Common Common Multiple (LCM)'. The instructor begins the lesson by explaining the concept of LCM for decimals, setting the stage for the method to be demonstrated.

  2. 2:00 – 5:00 02:00-05:00

    The instructor begins the first example, LCM(2.8, 0.63). He explains the method of converting decimals to whole numbers by multiplying by 100, as both numbers have two decimal places. The on-screen text shows the conversion: (2.8, 0.63) x 100 = (280, 63). He then proceeds to find the LCM of 280 and 63 using prime factorization. The board shows the factorization: 63 = 7 x 9 = 7 x 3 x 3, and 280 = 7 x 4 x 10 = 7 x 2 x 2 x 2 x 5. The LCM is calculated as 7 x 2 x 2 x 2 x 3 x 3 x 5 = 2520. The final step is to divide this result by 100, yielding 25.20 as the LCM of the original decimals.

  3. 5:00 – 7:23 05:00-07:23

    The video presents a second example: LCM(0.18, 0.24, 0.3). The instructor explains that the highest number of decimal places is two, so the numbers are multiplied by 100. The conversion is shown as (0.18, 0.24, 0.3) x 100 = (18, 24, 30). He then finds the LCM of 18, 24, and 30. The prime factorization is shown: 18 = 2 x 3 x 3, 24 = 2 x 2 x 2 x 3, and 30 = 2 x 3 x 5. The LCM is calculated as 2 x 2 x 2 x 3 x 3 x 5 = 360. The final answer is obtained by dividing 360 by 100, resulting in 3.60. The video concludes with a 'THANKS FOR WATCHING' screen.

The video provides a clear, step-by-step guide to finding the LCM of decimal numbers, a topic that is often challenging for students. The instructor effectively breaks down the process into manageable steps: converting decimals to whole numbers, calculating the LCM of the whole numbers using prime factorization, and then converting the result back to a decimal. The use of two distinct examples reinforces the method and ensures the concept is well-understood. The visual aids, including the digital whiteboard and the instructor's clear explanations, make the lesson accessible and effective for learners preparing for competitive exams.