Unit 3 Contents

Estimating a Range of Answers

Nila, Irma, and Tanya were reading about gross things for their science project and learned that dust is made up of dead skin cells. Each person sheds about 30,000 to 40,000 dead skin cells a minute. This amount is expressed as a range. The low end of the range for the number of skin cells shed per minute is 30,000 and the high end of the range is 40,000. Any number between 30,000 and 40,000 is also a possible value for the number of dead skin cells shed in one minute.

1. What two convenient numbers should Nila multiply to find the low end of the range for the number of dead skin cells shed in a minute?
2. What two convenient numbers should she multiply to find the high end of this range?
3. What is the range for the number of dead skin cells that the students in Nila's school are shedding each minute?

Nila, Irma, and Tanya read that by the end of one year, the dust for one person weighs about 8 pounds.