# How do you write 18,000,000,000 in scientific notation?

$1.8 \cdot {10}^{10}$
1. Count the zeros: $9$
$\implies 18 \cdot {10}^{9}$
2. Usually is written in form: $\left(0 < \text{decimal number"< 10)*10^("numbers of zeros}\right)$
remember: $18 = 1.8 \cdot \textcolor{red}{10}$
$\implies 1.8 \cdot \textcolor{red}{10} \cdot {10}^{9} = 1.8 \cdot {10}^{9 + \textcolor{red}{1}} = 1.8 \cdot {10}^{10}$