First of all , we need to understand difference between mass and weight of a body it is not same thing .

Mass is defined as the amount of matter in a body , it is measured in kg .

It remains constant does not change from one place to another , since it is independent of gravity.

Where as weight is gravitational force from which we binds to the earth , it changes from place to place since it depends on gravity.

It is measured in Newton(N) , it is given by formula

W = M ×g ,

where ‘g’ is acceleration due to gravity on earth which is equals to 10 m/s² .

Moon

Now, we need to calculate weight on moon :

W = M × g(moon) .

g(moon) = g(earth)/6

W(moon) = W(earth) / 6 , for example if person is having mass 70 kg , then his weight on earth be 700 N where as his weight on moon will be 1/6 weight on earth.

Therefore , his weight will be 700/6 = 116.6 N

Hence , body weight on moon will become ‘1/6’ weight of body on earth planet .