Answer:
[tex]0.29\cdot10^3[/tex]
Step-by-step explanation:
Red blood cell: [tex]8.4\cdot 10^{-6}[/tex]
Grain of sand: [tex]2.4\cdot 10^{-3}[/tex]
The "how many times larger" part can be figured out by forming a ratio between the two diameters above:
[tex]\frac{2.4\cdot 10^{-3}}{8.4\cdot 10^{-6}} = \frac{2.4}{8.4}\cdot\frac{10^{-3}}{10^{-6}}\approx 0.29\cdot 10^{-3-(-6)}=0.29\cdot10^3[/tex]
Note that dividing the powers of ten corresponds to subtracting the denominator power from the numerator power of 10.
