Measurement in Chemistry-lab

during chemistry class yesterday we did a lab on the pan balance. We all learned how to use the pan balance accurately. We measured a penny, nickle, marble, black rubber stopper, green rubber stopper, container of water, fishing weight, small test tube, small glass bottle, paper Dixie cup, and a plastic cup. first we predicted what is the mass or volume then we measured it. After we measured it, we did some math to see how many percent we are off on our predictions.