The answer would be 7.76e-5 or 7.76×10^-5. A gram is equivalent to 1000 milligrams, that would be a part of our first ratio.
Set up two ratios:
1000mg/1g=0.0776mg/y
Please be aware that y is a variable.
Cross multiply and you would have:
.0000776=gram
If you were to write it in scientific notation, that would be 7.76e-5.