U.S. students spend more time in K-12 schools than their peers in many other countries. In fact, in Japan and South Korea, kids spend an average of about 150 fewer instructional hours per year in school, yet these students consistently score higher on international tests. How is that possible?

In both countries, competition to attend elite universities is extremely rigorous. It's common for students to get extra help with private tutoring and night classes, known as 'cram schools'.

In Japan, 'cram schools' or jukus are offered to kids as young as four years old -- to help get them into private kindergartens.

In South Korea, some cram schools stay open as late as 11:00 PM, so high school students can better prepare for college entrance exams. These extra hours aren't counted as time spent in school, but evening classes are a huge part of a student's life.

Read the full article on American schools by Alice Roth at The Atlantic