Can someone explain me what this math's method does?

Question

i have seen this following math method called:

Math.round(d*10000) / (double) 10000;

and i don't know what it means. can someone please explain me ? thank you

Answer 1

Assuming d is a double or float . It multiplies d with 10000 . Rounds to the nearest whole number, and divides by 10000

If effect, it returns the original number with '4 digits as decimal fraction' (without resorting to formatting to String and parsing)