Weight and Mass are different things but weighing scales are designed to estimate the mass sitting on them and so instead of units of force it is common to use units of mass like these. A unit of heaviness or mass as the pound. A piece of metal known to weigh a definite amount.
Amount a thing weighs.
On it he or she explains that your final grade will be determined in this manner. Otherwise multiply each weight w by its matching value x sum that all up and divide by the sum of weights. The amount or quantity of heaviness or mass. The quantity of matter in an object.