The appliance measures weight through its feet, meaning ypu can weigh anywhere on your machine; in the bowl, at the high speed outlet, or even on the head. The weighing is accurate to measure in 1g increments, so any movement near to the appliance may cause the display to change. Also if you lean on the bowl whilst filling it with food you are adding to the weight on the machine so it can also cause an additional weight reading. Always make sure the appliance is on a flat, even surface when weighing.