how come 0 wont appear at end of decimal place

Can someone please help me why JAVA wont display the zero at the end of the decimal place. for instance,

double A = 6.000

by right A = 6.000

However, when i execute this System.out.println(A);

output of A = 6.0

Can someone tell me how do i keep the the value to 6.000. Not possible for me to use decimalformat class because I need variable A to be a double.

I write a program that round off value to 2 decimal places, However, it will only appear as 20.0 when the value is suppose to be 20.00, or show only 5.6 when it suppose to be 5.60. can someone please tell me how to solve this problem. thank in advance!