### Theory:

We can use decimals to measure the weight of the object.

Kilogram$$(kg)$$, Gram$$(g)$$ and Milligram$$(mg)$$ are the measurements used to measure the weight of the object.
$\begin{array}{l}1\phantom{\rule{0.147em}{0ex}}g\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}\frac{1}{1000}\phantom{\rule{0.147em}{0ex}}\mathit{kg}=0.001\phantom{\rule{0.147em}{0ex}}\mathit{kg}\\ \\ 1\phantom{\rule{0.147em}{0ex}}\mathit{mg}\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}\frac{1}{1000}\phantom{\rule{0.147em}{0ex}}g=0.001\phantom{\rule{0.147em}{0ex}}g\end{array}$
Example:
1. Convert $$65$$ $$g$$ to $$kg$$.

$\begin{array}{l}1\phantom{\rule{0.147em}{0ex}}g\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}\frac{1}{1000}\phantom{\rule{0.147em}{0ex}}\mathit{kg}\\ \\ 65\phantom{\rule{0.147em}{0ex}}g\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}\frac{65}{1000}\phantom{\rule{0.147em}{0ex}}\mathit{kg}=0.065\phantom{\rule{0.147em}{0ex}}\mathit{kg}\end{array}$

Therefore, $$65$$ $$g$$ $$=$$ $$0.065$$ $$kg$$.

2. Convert $$705$$ $$mg$$ to $$g$$.

$\begin{array}{l}1\phantom{\rule{0.147em}{0ex}}\mathit{mg}\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}\frac{1}{1000}\phantom{\rule{0.147em}{0ex}}g\\ \\ 705\phantom{\rule{0.147em}{0ex}}\mathit{mg}\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}\frac{705}{1000}\phantom{\rule{0.147em}{0ex}}g=0.705\phantom{\rule{0.147em}{0ex}}g\end{array}$

Therefore, $$705$$ $$mg$$ $$=$$ $$0.705$$ $$g$$.