# How do you write 21,000,000,000 in scientific notation?

##### 1 Answer
May 16, 2018

$2.1 \cdot {10}^{9}$

#### Explanation:

just count the number of digits after the first digit in the number, for decimals you have to take the decimal and count the number of zeros until you get to the first number that isnt zero, the power must be negative because you're going backwards
example:
0.00056
turns into $5.6 \cdot {10}^{-} 4$