To measure the mass of a given powdered substance do the following:
1. Zero the weighing balance, that is, put the weigh balance at zero mark.
2. Put an empty weighing paper on the balance and take its reading. Record it as X1.
3. Use spatula to put the powder you want to measure on the weighing paper on the balance. Take your reading and record it as X2.
The mass of the powered is X2 - X1.