Which of the following has the highest energy value?

Round up the following up to three significant figures:
$(i) 34.216$
$(ii) 10.4107$
$(iii) 0.04597$
$(iv) 2808$

How many significant figures are present in the following?
$(i)$ $0.0025$
$(ii)$ $208$
$(iii)$ $5005$
$(iv)$ $126.000$
$(v)$ $500.0$
$(vi)$ $2.0034$

Perform the following calculations for the given exponential numbers:
$(i)$ $(6.7 \times 10^4) \times (8.4 \times 10^7)$
$(ii)$ $\frac{(3.4 \times 10^{-3})}{(6.5 \times 10^{-7})}$

Which prefix used in the $SI$ system has a multiplier of $10^{-6}$?

Which is the heaviest among the following?