You have cement block placed on earth and moon with same mass. When you try to push the block it would be easier to push the block on moon than on earth i.e. the inertial property shown by block on earth is more than it shows on moon. But the mass is same on earth and moon. When you have inertia different and mass same how can you tell mass is measure of inertia? Weight should be the measure of inertia. Right?