A balance is used to measure mass. Normally it has one control: the control bar. If the balance is off, switch on the display. Briefly press the control bar which is sometimes written as “T”, the balance will eventually read 0.00, 0.000 or 0.0000 g depending on the scale of that balance.
To weigh an item, simply place that item on the pan. If you want to weigh a chemical, do not place that chemical directly on the pan. You must put that chemical on a weighing paper, or in a beaker or a watch glass. The balance will automatically subtract the weight of the container if the following process is performed