Students flocked to economics-related courses this spring, with Economics 10 defending the title it held in the fall as the largest course of the semester and spring’s Statistics 104: “Introduction to Quantitative Methods for Economics” coming in second place.

Economics 10, the historically popular course headed by N. Gregory Mankiw, began its second semester with 638 undergraduates, slightly more than a 50-person decrease from last spring. As usual, the second semester of the yearlong course saw a moderate decrease from its fall enrollment of 719 undergraduates.

Statistics 104 saw a marked increase in students since last spring. With 554 undergraduates currently enrolled, the class boasts more than 200 more students than it did last year.

Computer Science 51, the sequel course to the popular introductory class Computer Science 50, also displayed a substantial increase, from 164 undergraduates last spring to 217 this semester.

Some professors of these popular offerings credited the practicality of their subject matter with attracting students.

“I am delighted that Ec 10 is the largest course once again,” Mankiw wrote in an email. “Understanding the basics of how an economy functions is a key element of good citizenship, and it is good to see so many students appreciating that fact.”

John G. Morrisett, who teaches Computer Science 51, said that “the vast majority” of his students—who number about a third of the enrollees in the fall prerequisite Computer Science 50—had no intention of concentrating in computer science before taking the first course in the sequence. After a semester, though, Morrisett said they came to see value in furthering their studies in the field.

“Many students seem to see a concentration, or at least a minor, in computer science as a good idea,” Morrisett wrote in an email. “These days, students recognize that it’s important to have some computational thinking in their intellectual bag of tools, regardless of what they hope to do later in life.”

The most dramatic increase of the semester was seen in Science of the Physical Universe 30: “Life as a Planetary Phenomenon.” Enrollment shot up 285 percent, from 92 undergraduates last spring to 354.

According to Dimitar D. Sasselov, who teaches the course, it was mistakenly listed as unavailable in the online course catalogue last spring, which dissuaded students from shopping it. Though Sasselov said he anticipated an increase once his class had a proper listing, this year’s high exceeded his expectations.

Many professors said the student rankings in the online Q guide swayed shoppers’ choices this year.

Population ethics professor Daniel Wikler guessed that the Q guide ratings for his class Ethical Reasoning 24: “Bioethics” were a major factor behind the course’s drop from 127 undergraduates to 18. The overall Q guide score for Ethical Reasoning 24 is 2.88 out of 5.

—Staff writer Gina K. Hackett can be reached at ghackett@college.harvard.edu.