# How do you write 67.2 million in scientific notation?

Sep 17, 2016

$67.2$ million is $6.72 \times {10}^{7}$ in scientific notation.

#### Explanation:

In scientific notation, we write a number so that it has single digit to the left of decimal sign and is multiplied by an integer power of $10$.

Note that moving decimal $p$ digits to right is equivalent to multiplying by ${10}^{p}$ and moving decimal $q$ digits to left is equivalent to dividing by ${10}^{q}$.

Hence, we should either divide the number by ${10}^{p}$ i.e. multiply by ${10}^{- p}$ (if moving decimal to right) or multiply the number by ${10}^{q}$ (if moving decimal to left).

In other words, it is written as $a \times {10}^{n}$, where $1 \le a < 10$ and $n$ is an integer.

Now $67.2$ million is $67.2 \times 1000000$

= $6.72 \times 10000000$

= $6.72 \times {10}^{7}$