Measure and estimate the weight, length, or volume of objects.

Measuring is a specific kind of observation skill. Scientists routinely measure weight and volume with balances and graduated cylinders. They often use common tools for measuring length.

Estimating is a valuable skill because it can help in selecting the proper equipment and supplies. Estimating can also help avoid making mistakes in expressing answers. If you have a good rough idea of the correct answer, you can compare your calculated answer to make sure that you are in the correct ballpark.