Physics Books in HKUST Library — Example solution (Issue 027)
There are 2,442,592 books in the HKUST Library. Books in a library can be classified into 26 categories according to the Library of Congress (LC) Classification System, including science as one category. There are four subjects[DL1] of science in general (mathematics, physics, chemistry and biology).
The estimated order of magnitude of the quantity of physics books in the HKUST Library:
2,442,592 books / 26 categories / 4 subjects
= 23,500 books (correct to 3 significant figures)
= 2.35 x 104 books
∴ The estimated order of magnitude is 104.
Can you come up with your own answer? The actual order of magnitude of the size of our physics book collection (including e-books) is 104 (38,268 books).
*The number of 38,268 includes both astronomy and physics books (subclasses QB & QC) in the LC Classification System.