# There are 1,000 mg in every gram. If something has a mass of 458 mg. what is the mass expressed in grams?

$1$ $m g$ $=$ $1 \times {10}^{-} 3 \cdot g$
$458$ $m g$ $=$ $458$ $\cancel{m g}$ $\times$ ${10}^{-} 3 \cdot g \cdot \cancel{m {g}^{-} 1}$ $=$ $0.458 \cdot g$