Are the Chinese better at math than Americans?

Econ 001 

Ever since our financial meltdown, the US has been accusing China of 'currency manipulation'. These accusations are in spite of the fact that the Yuan has risen nearly 20% from 2005-2008 and the US imported at least as much in those years as we do now.

Somehow this just seems too simple to bother with economists, treasury secretaries, or in particular the financially astute US politicians.

Ready?

-Most exports from China to the US are only ASSEMBLED in China (such as Apple's iPod where the China export value input to an iPod is about $18). Since the Chinese input to this export constitutes no more than 10% of such export, another 20% appreciation in the Yuan would AT MOST increase the price of these exports by 2%. 

-Then, the appreciation of the Yuan may cause China to LOSE these jobs to other countries (Vietnam, India) which will reduce the buying power of Chinese to buy (import) US goods

Therefore, it is not the currency. Labor is the most significant component of most goods exported from China to the US. If wages go up in China then prices of its exports will rise which is what US is hoping to achieve by increasing the value of the Yuan.