Is it true that Americans are very bad at mathematics? If yes, then why?

Yes. Americans are very bad at math. For example, the population of China stagnated from 1840 to 1949 at the level of 400 million. During the 27 years of the Mao Era, the population of China doubled from 400 million to 800 million. Yet all Americans believe Mao killed 30 million to 100 million Chinese. Americans believe Mao killed more Chinese after 1949 than the whole causality of WWII. Even American professors believe this picture. They all believe the Mao Era was the darkest period in Chinese history even though the population doubled during Mao while the population before Mao stagnated for a century. The math just doesn’t add up. It looks as that American math education deliberately keep American fooled so that American people can be easily brainwashed.