THE ONE WORLD SCHOOL HOUSE: Education Reimagined. By Salman Khan. Twelve. 272 pages. $26.99.

“Oh, the math video guy!”

Salman “Sal” Khan is not yet a household name, having only recently nudged past tennis player Linda Tuero on the list of famous people from Metairie, La.

But to those who struggle with algebra, Khan’s voice is world-famous. His 10-minute YouTube explanation of factoring quadratic equations (to name just one) has been viewed more than a quarter-million times in less than three years. If you can generate that many views with high school algebra rather than stupid pet tricks, you must be doing something right.

In “The One World School House,” Khan tells his personal story and gives a glimpse of where education might be headed in the 21st century.

In a 272-page work whose breeziness well serves its cause, we learn that Khan’s interest in mathematics education, apart from his own education at MIT, began when he agreed to tutor his 12-year-old cousin, Nadia, on a topic with which she happened to be struggling.

The operation proved successful, and Khan’s mind soon turned to leveraging that success through modern technology. His first attempt at a wider audience was tried out via Skype, but the live-action medium didn’t prove as scalable as he had hoped. Then a friend suggested that YouTube might be the answer.

Imagine you’re at a football game and somehow miss a key interception. Maybe you were getting a hot dog; maybe you were checking the clock; maybe you were watching the field all along but just plain missed it. In the absence of a replay on the Jumbotron, you’ve missed out on something that is vivid to everyone else.

To Khan, the missed moment isn’t an interception, it’s a unit conversion, a factored polynomial or anything from a curriculum whose obsession with forward movement ignores the virtues of the pause button.

To every student who has been distracted, tuned out or otherwise missed a key classroom discussion, Khan is offering the same free-of-charge second chance he offered young Nadia.

A chance to learn, at whatever pace feels appropriate, in the comfort of home. A chance to avoid the death spiral of poor grades, downward reclassification, loss of confidence and more poor grades. Khan’s videos now cover topics well beyond algebra, even well beyond mathematics. His business, begun out of a closet in 2004, has now received seed money from the likes of Bill Gates.

Today, the math video; tomorrow, the transformation of education? You will note the enormous leap.

Frankly, some of Khan’s book reads as though he is picking up theories of education on the fly. What implications do videos have for curricula? For grading? Where do class sizes fit in? What about class lengths, for that matter?

The book is Khan’s forum to talk about all this and more. But even if his mental meanderings feel grandiose, they carry a vital message in their subtext, because they are the very types of explorations that a curious mind should be encouraged to pursue.

His ideas are laid out with such clarity that the readers could be forgiven for imagining that they dreamed them up themselves.

Perhaps a more valid criticism is that in Khan’s world, all children seem to be above average, just as they are in Lake Wobegon. Nadia, for one, is obviously way above average in both capability and curiosity.

But what Khan is really saying is that at any given moment, students who are experiencing a temporary blip can get designated as underperforming by a well-meaning system, and those students are capable of dramatic improvement.

In that sense, being above-average needn’t be such an exclusive club. That appears to be the standard that Khan has set.

Reviewer Derrick Niederman is a math professor at the College of Charleston.