Question

Use the following scenario to answer the question below:

When the new book units of fire was released, Johnathan 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 of minutes he spent reading.

To figure out how many minutes he read, what is a conversion ratio he should use?


`A. (9.30 minutes)/(1 hour)`

`B. (1 hour)/(60 minutes)`

`C. (60 minutes)/(1 hour)`

`D. (60 hours)/(1 minute)`

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.)