20 Chapter 2 9. Use a calculator to evaluate the value of each of 10. The population of a city is 2.64 X 10 and the following expressions. (Give the answers the area of the city is 1.12 X 10' km . Find the correct to 3 significant figures and express the population density of the city in people/km? results in scientific notation.) Give the answer correct to 3 significant (a) 5 300 4 + 4 700 figures and express the result in scientific 11 6 notation.) (b) (492 X 283) : (2012 X 1023) (c) 41 507 Solution 3.14 x 10 (d) (7.1 X 10 x 4 100 ) 2.67 X 10-7 Solution 11. The thickness of a piece of paper is 9.6 X 10 ' m. If the thickness of a pile of A4 paper is 38 cm, estimate the number of pieces of A4 paper in the pile. (Give the answer correct to the nearest integer.)