A moon rock collected by the Apollo Mission is estimated to be $3\mathrm{.}80$ billion years old by uranium$/$lead dating. Assuming that the rock did not contain any lead when it was formed, what is the current mass of ${?}^{206}Pb$ in the rock, given that it currently contains $1\mathrm{.}180g$ of ${?}^{238}U?$

The half$-$life of ${?}^{238}U$ is $4\mathrm{.}47{10}^9$ years.

Report your answer in grams $($do not include the units in the response box$)$

HINT: The decay process is ${?}^{238}U{?}^{206}Pb,$ you will need to account for the differences in the mass of the isotopes in your calculation.