In part 1, you are asked to measure the density of four objects. Measure the objects mass by using the mass scale. A vernier caliper is a precision measuring instrument which can be used to determine the dimension of an object to two decimal places of accuracy, e.g. 1.23 cm. It should be used to measure the relavent dimensions for each object. From this, the volume can be determined.
Density is the ratio of mass and volume.
Reading the vernier caliper for precision requires some practice. Click on the image to read the yellow print. The caliper has two graduations, on fixed, and another which moves. Locate the zero point. Here, the 0 point is just shy of 1.1 cm.