Convert from petagram to rebah

Unit Definition (petagram)
The petagram is a metric unit of mass equal to 10E15 grams or 1 gigatonne (one billion metric tons). This unit is used in atmospheric science and other scientific contexts where large masses are considered.

Unit Definition (rebah)
The rebah is an ancient Hebrew unit of weight or mass equal to 1/4 shekel. The word means "quarter" in Hebrew.