# How do you write 810,000 in scientific notation?

$8.1 \times {10}^{5}$
Count the number of times you need to shift the number to the right before it's less than $10$. This gives you the exponent.
If you started with a number less than $1$ then count the number of times you need to shift it to the left before it's greater than or equal to $1$.
For example, $0.0023 = 2.3 \times {10}^{- 3}$