6) Use a calculator to evaluate each of the following, leaving your answers in scientific notation correct to five significant figures.

b) √634 × 7.56 × 10⁷
d) − 8.9 × 10-⁴+ √7.6 × 10-³
f) 8.942 × 10⁴⁷ − 6.713 × 10⁴⁴/2.5 × 10¹⁹
h) 4 × 10⁸ + 7 × 10⁹/6
j)2.84 × 10-⁶ − 2.71 × 10-⁹/5.14 × 10-⁶ + 7 × 10-⁸