Final answer:
Rough order of magnitude estimates, useful in physics and engineering to approximate a value's 'ballpark figure,' are also known as preliminary estimates.
Step-by-step explanation:
Rough order of magnitude estimates are also known as conceptual estimates or preliminary estimates. These estimates are commonly used in physics and engineering fields to arrive at a rough idea of a quantity's value using prior experience and sound physical reasoning. A rough order of magnitude estimate, which may be informally referred to as a guesstimate or back-of-the-envelope calculation, is not a detailed or final estimate. It is a way to use simple arithmetic and physical principles to determine whether a value is within a reasonable range, referred to as the 'ballpark figure'.
Estimations involve using strategies to approximate values, keeping the calculations to one significant figure, and conducting sanity checks to ensure the plausibility of the results. Familiarity with dimensions, units, and the scales of base quantities aids in making more accurate estimates.
The answer to the student's question is 1) Preliminary estimates.