Answer:
You just stack them like you would a normal multiplication problem so 67.8
.45
and them multiply them like you would a normal problem so ignore the decimals for now. Once you have your answer, look at how many numbers are behind the decimal in both number (in this case it's 3) so then you would take your answer and move the decimal over three sooooooo 30510 would be 30.510 or just 30.51
Explanation: