I died laughing at an actual Chinese math textbook, it's from 1969, the time of the Great Proletarian Cultural Revolution.
The cover

WTF...Mao!!!

Now, a page from chapter one, logarithm

For my reader who doesn't understand Chinese, my translation is right here.

Farmer Zhang borrowed 3RMB from the evil land owner, after 10 months, compound interest to 3*(1+30%)^10, how much money is that
Operations....blah blah
Using the log table....(in China, )
After 10 months, the evil land owner exploit Zhang for a interest of 38.31RMB.

ok, it still looks reasonable... different culture produces... wait.. that's just too much

In the old sociality, land owners harshly exploit farmers for money by renting them land and use high interest rate, in the sinned haven created from all the labor's bones, there are millions like Zhang. If it isn't the chairman Mao's leadership helping us throw over the three mountains pressuring on all the labor's head and create a rule of the proletariat...

I stopped there, the praise for Mao will go on till the next page, with various quotes from him about how the fight against classes should still go on.
I'm glad no one is using that kind of textbook anymore.