to determine the product between the 2 numbers we must write both numbers in scientific notation
[tex]800.5=8.005\cdot10^2[/tex]now we multiply both number without the tenth potency.
[tex]8.005\cdot2=16.01[/tex]now we add the tenth potencies
[tex]\begin{gathered} 16.01\cdot10^{6+2} \\ 16.01\cdot10^8 \end{gathered}[/tex]now we move 1 decimal place more to the left to make the number between 0 and 9.9
[tex]16.01\cdot10^8=1.601\cdot10^9[/tex]