Lining up the decimals and subtracting just like you do with whole numbers is the best way to approach the subtraction of decimal values.
.551 .832 - .430 - .122 ------- ------- .121 .710 .476 .693 - .353 - .371 ------- ------- .123 .322
.333 - .222 = .111 .452 - .221 = .231 .454 - .131 = .323 .991 - .100 = .891
Now you get to try a few for yourself.