# How do you write 22,000 mg in scientific notation?

$2.2 \times {10}^{4} \setminus \text{mg}$
First, move the decimal place until you get a coefficient between $1$ and $10$. In here, it's $2.2$.
Then, count the digits away from the decimal place. Here there are $4$. Therefore, it's ${10}^{4}$.