Deceptive Decimal Notation  - with examples [Ganita Prakash Class 7] - More on Decimal System

part 2 - Deceptive Decimal Notation - More on Decimal System - Chapter 3 Class 7 - A peek beyond the Point (Ganita Prakash) - Class 7 (Ganit Prakash)
part 3 - Deceptive Decimal Notation - More on Decimal System - Chapter 3 Class 7 - A peek beyond the Point (Ganita Prakash) - Class 7 (Ganit Prakash)

Share on WhatsApp

Transcript

Deceptive Decimal Notation Can you figure out what’s the mistake here? Sarayu gets a message: “The bus will reach the station 4.5 hours post noon.” When will the bus reach the station: 4:05 p.m., 4:50 p.m., 4:25 p.m.? None of these! Here, 0.5 hours means splitting an hour into 10 equal parts and taking 5 parts out of it. Each part will be 6 minutes (60 minutes/10) long. 5 such parts make 30 minutes. So, the bus will reach the station at 4:30. Here is a short-story of a decimal mishap: A girl measures the width of an opening as 2 ft 5 inches but conveys to the carpenter to make a door 2.5 ft wide. The carpenter makes a door of width 2 ft 6 inches (since 1 ft = 12 inches, 0.5 ft = 6 inches), and it wouldn’t close fully. If you watch cricket, you might have noticed decimal-looking numbers like ‘Overs left: 5.5’. Does this mean 5 overs and 5 balls or 5 overs and 3 balls? Here, 5.5 overs means 5 5 overs (as 1 over = 6 balls), i.e., 5 overs and 5 balls. Where else can we see such ‘non-decimals’ with a decimal-like notation?

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 15 years. He provides courses for Maths, Science and Computer Science at Teachoo