# An adult has 206 bones. Of those, approximately 2.9% are found in the inner ear. About how many bones in the human body are found in the inner ear?

May 14, 2016

$6$ bones

#### Explanation:

The two steps to solving this problem are:

$1$. Converting 2.9% into a fraction.
$2$. Multiplying the fraction form of 2.9% by the total number of bones in the human body.

Rewriting 2.9% as a Fraction
Since % means "out of hundred," put $2.9$ over $100$.

2.9%

$= \frac{2.9}{100}$

As there cannot be any decimals in a fraction, you must get rid of the decimal. You do this by multiplying the numerator and denominator by $10$.

$= \frac{2.9}{100} \left(\frac{10}{10}\right)$

$= \frac{29}{1000}$

Determining the Number of Bones Found in the Inner Ear
Multiply $206$ bones by $\frac{29}{1000}$.

$206 \textcolor{w h i t e}{i} \text{bones} \cdot \frac{29}{1000}$

Since $206$ and $1000$ can be divided by a common factor of $2$, their values are reduced.

$= 206 \textcolor{red}{\div 2} \textcolor{w h i t e}{i} \text{bones} \cdot \frac{29}{1000 \textcolor{red}{\div 2}}$

$= 103 \textcolor{w h i t e}{i} \text{bones} \cdot \frac{29}{500}$

Solve.

$= 5.974 \textcolor{w h i t e}{i} \text{bones}$

$\approx \textcolor{g r e e n}{| \overline{\underline{\textcolor{w h i t e}{\frac{a}{a}} \textcolor{b l a c k}{6 \textcolor{w h i t e}{i} \text{bones}} \textcolor{w h i t e}{\frac{a}{a}} |}}}$