weighing machine calculates weight or mass

Most 11 year olds learn the following in physics,

Weight is usually measured in kgf ('kilograms force') which we shorten to 'kilograms' in conversation. On Earth a mass of l kg has a weight of l kgf (=appx 9.81 Newtons) due to the Earth's gravity and hence a 'weighing machine' also gives a measure of 'mass' because mass and weight on Earth are numerically equal.

That's not what I learnt. I was told the mass of the ass equals the heat of the meat over the angle of dangle. It might have been Physics, PE or Applied Dance, one of the sciences anyway.

The lift scenario is irrelevent because the above numerical equivalence is valid only for vertically stationary objects on Earth without further acceleration affecting g=9.81 m/s^2

You obviously never had Killer Crouchly teaching you !

No I had Plumbum, he was a Physics teacher who was also a Mormon who taught RE. He was worse than useless, if I'd not moved to another school I'd have failed my O level.

They don't make em like they used to. OFSTED has spoiled all the fun !