Perform the mathematical operation, and then write the final answers, rounded to the correct number of needed significant figures you must use the exact number of significant figures or decimals.

A.200.0 + 20=
B. 405 x 30=
C. 0.8020 / 0.70=
D. 740.0 - 70.1234=
E. 824.6 + 3.2000 + 1.21=