Sure, here is the translation of the text you provided:
```html
And so it happened that Chu Xuan, who originally came just to deliver a book, settled down at the Celestial Secret Peak to study astrology.
Xuanyuzi said it would take three days, but Chu Xuan finished in a day, even asking in return, "Is it really this simple?"
This left Xuanyuzi dumbfounded, as he had indeed been bluffing Chu Xuan before; after all, mastering celestial calculations is very much about innate talent. Some people just can't learn it no matter what, like a blockhead.
Even though Chu Xuan possessed the Innate Dao Body, which should logically enable him to excel in cultivation, Xuanyuzi initially didn't have high hopes because cultivation and divination, despite some similarities, are essentially different.
According to Xuanyuzi's estimations, if Chu Xuan could learn it in three months, it would be considered good enough. Yet, he mastered it in a day, leaving the elder utterly bewildered.
