Question

When the new book Units of Fire was released, Jonathan decided to read it in one sitting for his book report. He started at 11:00 a.m. on Saturday morning and read until 8:00 p.m. that night, for a total of 9 hours. For school, however, he needed to record the exact number he spent reading. What is the Order of Magnitude of the number of seconds he reads?

Answer 1

9 hr * 60 min/hr = 540 min. 540 min * 60 sec/min = 32,400 sec. Use the method described by panic mode: round the number down until there is only one non-zero digit left. Here, 32,400 rounds down to 30,000. Now count the number of zeroes; the result is the order of magnitude: 4. (You see this in scientific notation also: 30,000 = 3 × 10^4.)