Ten-year-old Danny Portillo studies multiplication problems on a tablet computer, using video lessons by LearnZillion. - 

Kai Ryssdal: For those who haven't been in a modern public school classroom lately, there have been some changes since the days you had to whack the erasers together after class to clean them out. Chalkboards have been replaced not just by whiteboards, but by high-tech "smart" boards. Students are using laptops and iPads all over the place. In all, public schools spend roughly $3 billion a year on education technology -- things meant to make teaching faster, easier and better.

Change can be hard, but companies are trying to ease the transition. From the Marketplace Education Desk at WYPR, Amy Scott reports.

Amy Scott: In a fifth grade classroom at DC Bilingual Public Charter School in Washington, students break into small groups to study math. One group guesses the dimensions of an imaginary dog house.

Students: Oh!

Teacher: Who had the dimensions?

 Another group tackles area and perimeter.

 Teacher: So what can you say about the sides of a square?

 And one boy sits on his own wearing headphones, watching a video on a tablet computer. He’s learning how to solve two-digit...

Video: …by two-digit multiplication problems using the partial products method. 

 The video is on a website called LearnZillion. It has hundreds of free, five-minute math lessons, for grades three to nine. A voice -- that young-sounding teacher you just heard -- explains how to solve problems as illustrations appear on a whiteboard. Ten-year-old Danny Portillo follows along with a pencil and paper.

 Video: Now, I want you to stop the video, and see if you can do it by yourself. 

A few other students have been struggling with decimals. Instead of meeting with them individually, or just moving on, teacher Jacquelyn Vivalo sets them up on LearnZillion. She can create a custom playlist of online lessons for each student, and track their progress.

Jacquelyn Vivalo: It allows us to be in more places at once. And also be able to help and support the students who are working on different content at the same time.

Tom Carroll: Customizing learning has been the Holy Grail in education for decades.

Tom Carroll is president of the nonprofit National Commission on Teaching and America’s Future.

Carroll: We have a much more diverse student population than we’ve ever had before -- diverse in learning background, skills, languages.

LearnZillion is among a handful of sites aiming to meet those different needs. You may have heard of the Khan Academy, a repository of free online videos on all kinds of subjects. Eric Westendorf is one of LearnZillion’s founders. He’s a former principal at E.L. Haynes public charter school in D.C. Westendorf says what distinguishes LearnZillion’s videos is that they’re made by school teachers.

Eric Westendorf: I knew that there were so many folks out there who had figured out over time ways of explaining things really clearly that really worked. And we wanted to tap into that expertise out there.

Teachers can tap that expertise to see how other teachers teach. Andrea Smith teaches sixth grade math at E.L. Haynes.

Andrea Smith: If I had had this when I started teaching, it would have saved me a lot of time researching things on my own, and a lot of probably trial and error on my students.

Parents can also use the free videos to brush up. Don’t tell me you remember how to determine the end behavior of a polynomial function. The company plans to make money by charging parents a small fee to follow their kids’ progress, and by selling extra services to schools. It pays teachers $100 for each video they make.

Judith Haymore Sandholtz is a professor of education at the University of California, Irvine. She says even good videos can’t replace the interaction between a live teacher and student.

Judith Haymore Sandholtz: The bottom line is this doesn’t give you access to students’ thinking. And if students have misconceptions along the way, you need to have an approach that will allow you a window into their thinking.

LearnZillion has quizzes so teachers can see what students have learned. Advocates of instructional videos say they give teachers more time to interact with students. With the basic lessons covered, teachers can focus on helping students learn to apply them.

In Washington, I’m Amy Scott for Marketplace.

Follow Amy Scott at @amyreports