Quick. Picture your son sitting in a college class.

Got that picture in your mind?

Let me guess what you just imagined. You pictured him absorbed in his college lecture. You pictured him paying close attention to every word the professor is saying. You pictured him diligently filling page after page with carefully organized notes.

You may have just imagined wrong.

The typical college student squanders one-fifth of his class time doing this.

Texting. Emailing. Checking Facebook. Surfing the web. Playing games on a phone, tablet, or laptop.

A 2015 University of Nebraska-Lincoln study of 675 college students across 26 states reveals that nine out of ten students report that texting is “their main diversion during class.”

About 75% of students polled admitted to emailing or checking the time on their phones. 70% reported scrolling through Facebook and other social media during the time they were supposed to be learning. Nearly half surfed the web during class, and one in 10 spent class time playing games.

What’s the cost to parents? Let’s do the math.

Let’s say your son attends a private university that charges $5,880 for a 3-credit course. If your son texts, emails, checks social media, surfs the web, or plays games during just one-fifth of his class time, which is a lowball estimate, that diversion will end up costing your family $1,176 for each class he takes. If your son takes 18 credits per term during every term other than his first one on campus — as I advise students to do in order to graduate faster — this seemingly innocuous habit will cost your family $7,056 per term. $28,000 or more over the course of an entire four-year college career.

Not to mention the cost to your son when that knowledge base isn’t available to him when he tries to enter the workforce later.

It’s no wonder today’s college students are having trouble getting real jobs after college.

I have a magical way to solve this problem.