A brief overview of the use of certain and uncertain digits in measurement.

This lesson should help a learner understand why estimates are used when making calculations. It is 3 of 4 in the series titled "Introduction to Estimating."

This lesson explains how triangles and parallelograms can be used to estimate the area of a circle. It is 4 of 4 in the series titled "Estimating the Area of a Circle."

This slide show presentation introduces the concept of order-of-magnitude, and how it is used to estimate large values in physics.

A guided lesson explaining how to add and subtract numbers expressing the answer with the appropriate number of significant digits.