The Marketplace K-12 team examined our data to see what stories received the most views on our blog in 2013. Three of the top 10 centered on the impact of the Common Core State Standards. Our most popular post revealed how much teachers are spending, personally, on their students’ education. Check out what else made the list:

1. Survey: Teachers Digging Into Own Pockets to Buy Education Products

Teachers spent about $3.2 billion on various types of supplies and materials during the 2012-13 academic year, according to a National School Supply and Equipment Association survey. Half that total amount, $1.6 billion, came out of educators’ own pockets.

2. Global Education Market Tops $4 Trillion, Analysis Shows

The global market for education is $4.4 trillion, and poised to grow 23 percent over the next five years, according to an analysis by an international investment bank that advises companies on educational technology.

3. Amplify Insight Wins Contract from Common-Core Testing Consortium

The Smarter Balanced Assessment Consortium, which is one of two consortia developing tests for the Common Core State Standards, awarded a $12.5 million contract in March to Amplify Insight to develop a digital library of formative assessment professional learning tools for educators.

4. Business Execs: Fight for Common Core Before It’s Too Late

In September, representatives of major corporations urged their peers in the business community to take up the fight to defend the Common Core State Standards—warning them to steel themselves for opposition from some quarters, and apathy from others.

5. Ed-Tech Chief Posits Five Innovation Questions for Schools

School leaders using technology to promote innovation in the classroom should consider five critical questions, according to Richard Culatta, the director of the Office of Educational Technology for the U.S. Department of Education. Among them: How are we using data? How are we using “open resources?” And, how do we personalize learning?

6. ‘MOOC’ Provider Coursera Moves Into K-12 Teacher Training

Coursera—a major player in the world of “massively open online courses” in higher education—made its first move into the K-12 arena through an effort to provide free training and professional development to teachers in the United States and other countries.

7. iPads the Mobile Technology of Choice in Schools, District Officials Say

A survey released in July indicated that the iPad is the king of the mountain when it comes to school officials’ current use of mobile technology. More than 80 percent of district technology officials said districts use—or plan to use—iPads over the next year or two. Google Chromebooks came in a distant second.

8. Goldman Sachs Makes Investment, Gets Returns on Utah Preschool Program

An innovative partnership involving Goldman Sachs, a school district in Utah, and several community charities could expand that school system’s early-education program while also saving taxpayers money and earning returns for the investment bank.

9. Pearson Reaches $75 Million Settlement in E-Book Complaint 

A division of Pearson, the worldwide publisher of education products and other materials, agreed in May to pay $75 million as part of a settlement of a lawsuit in which a group of companies was accused of fixing the price of e-books.

10. Publishers Confront Challenges of Crafting Common-Core Materials

In June, two experts who are helping educators implement the Common Core State Standards gave education publishers a brief tutorial on those multistate academic guidelines. In turn, they were given an update from industry representatives on what they’re hearing from customers in K-12 systems that are buying their products.