X ces Science often deals with very large or very small numbers. To make these numbers more manageable, we use scientific notation to indicate the scale of the number. Convert the values in the table to scientific notation and fill in the table. Labels 5 x 103 5 x 10-4 5 x 106 Drop Zones ← Reset All Standard Notation Scientific Notation .00005 0.05 5 x 101 5 x 10-1 500 50,000 5,000,000 5 x 102 5 x 10-2 5 x 10-5

a. There are 365 days per year, 24 hours per day, 12 months per year, and 60 minutes per hour. Use these data (o deter- mine how many minutes are in a month. b. Now use the following data to calculate the number of minutes in a month: 24 hours per day, 60 minutes per hour, 7 days per week, and 4 weeks per month. c. Why are these answers different? Which (if any) is more correct? Why?

What is the difference in surface area between two circles, one of radius 7.98 cm, the other of radius 8.50 cm? The surface area of a circle of radius r is r2. Obtain the result to the correct number of significant figures.

Although the preferred SI unit of area is the square meter, land is often measured in the metric system in hectares (ha). One hectare is equal to 10,000 m2. In the English system, land is often measured in acres (1 acre = 160 rod2). Use the exact conversions and those given in Exercise 47 to calculate the following. a. 1 ha = __________ km2 b. The area of a 5.5-acre plot of land in hectares, square meters, and square kilometers c. A lot with dimensions 120 ft by 75 ft is to be sold for 6500. What is the price per acre? What is the price per hectare?