roundSignificand

Round using specific DecimalMode and return rounded instance. This is applied only to significand.

I.e.: 1.234E3 == 1234, rounded with DecimalMode(2, RoundingMode.CEILING) will return 1.3E3 == 1300

1.234E-3 == 0.001234, , rounded with DecimalMode(2, RoundingMode.CEILING) will return 1.3E-3 == 0.0013