The population of spain is 47,042,000. the population of romania is 21,400,000. round each number to the nearest ten million. what is the combined population of the two countries? a. 60,000,000 b. 68,000,000 c. 68,300,000 d. 70,000,000

D.70,000,000 because 21 million rounded to the nearest ten million is 20 million and 47 million rounded to the nearest ten is 50 million 50 million plus 20 million is 70 million which is letter D

Total population = Population of Spain + Population of Romania
= 47,042,000 + 21,400,000
= 68,442,000
{Round this number off to the nearest 10 million or 10,000,000. The digit at the 1 millionth placing, 1,000,000, is 8 in this case. So, the number in the 10th millionth digit placing, 6, should be rounded off to 7, and the rest of the digits will become 0.}
= 70,000,000 (rounded off to nearest 10 millionth)

You should only round off the number after you have added the two populations up.

There may be some people who would round off the separate population numbers of both Spain and Romania before adding them up. This is incorrect, since it may or may not get you the answer you may be looking for, aka. the best estimate.

Hope this helps! :)