Final answer:
To find the area of the Earth in square kilometers (km²), we need to convert the given surface area of 196 million square miles to square kilometers. The area of the Earth in square kilometers is approximately 510 million km².
Step-by-step explanation:
To find the area of the Earth in square kilometers (km²), we need to convert the given surface area of 196 million square miles to square kilometers. We know that 1 mile is approximately equal to 1.60934 kilometers. So, we can multiply the surface area in square miles by the conversion factor to get the area in square kilometers.
196 million square miles x (1.60934 km/mile)^2 = 510 million square kilometers
Therefore, the area of the Earth in square kilometers is approximately 510 million km².