“O.K., what are you supposed to know?” Dad would ask the night before my midterm.

Dad, an immigrant from China who has a Ph.D. from Berkeley in electrical engineering and worked for a space optics company in Silicon Valley, would take notes silently as I spoke. Sometimes I could rattle off concepts from the syllabus — linear equations and inequalities, graphing lines and slope, quadratics and polynomials. Other times I listed specific chapters (“he covered everything from seven through 12”), the contents of which the rest of my class had spent the previous months learning.

Dad would then shoo me from the room for a few minutes so he could flip through my textbook alone.

My mom was the one who interpreted the rules, cooked meals, drove us around and volunteered to work the hot lunch line. Dad, on the other hand, was driving to the office before we woke up, and came back in time for a late dinner, the whole family often sitting around the table staring at pots of Chinese food my mom prepared, waiting for him to walk in the door so we could start eating.

While my mom was gregarious and emotive, my dad was the quiet observer and thinker — some might say stoic, or on a bad day, curmudgeonly.

But math and her friends like physics and astronomy were languages Dad spoke fluently.

With my older sister and brother, Dad would sometimes lose his temper when they couldn’t follow along, unable to understand why the expensive private schools he worked hard to pay for in California weren’t able to teach his kids the logic behind math. Or why his first-generation ABC (“American-born Chinese”) children were more interested in sports or the humanities than studying fractions and common denominators.