Your weight of 100 pounds on earth would be different on Mars.

Your mass would be the same, but your weight would be less because Mars has a weaker pull of gravity.

This weaker Martian gravity results from the smaller mass of Mars.

Mars has a mass of 6.4219 x 10²³ kg while the mass of the Earth is 59.72 x 10²³ kg.

The deceased weight would be

100 pounds x ( 6.4219 x 10²³ kg / 59.72 x 10²³ kg ) = 11 pounds