Based on the given information, you can write the area of Sahara desert as follow:
[tex]A=4.4(1.95\cdot10^6\operatorname{km})[/tex]In order to simplify the previous expression, multiply the coefficients 4.4 and 1.95, and put the same factor 10^6:
[tex]\begin{gathered} 4.4\cdot1.95=8.58 \\ A=8.58\cdot10^6\operatorname{km}^2 \\ A\approx8.6\cdot10^6\operatorname{km}^2 \end{gathered}[/tex]in scientific notation, you put only one number after the decimal point.
