In $2010$ Casey made a taxable gift of $$5\mathrm{.}1$ million to both Stephanie and Linda $($a total of $$10\mathrm{.}2$ million in taxable gifts$).$ Calculate the amount of gift tax due this year and Casey$$s unused exemption equivalent under the following alternatives. $($Refer to Exhibit $25-1$ and Exhibit $25-2.)($Enter your answers in dollars, not millions of dollars. Leave no answer blank. Enter zero if applicable.$)$

a$.$ This year Casey made a taxable gift of $$1$ million to Stephanie. Casey is not married, and the $2010$ gift was the only other taxable gift he has ever made.