Square root days happen only a few times in a century, and the man who brought the day fame is celebrating his sixth one.

This May marks the only time a calendar has a Square Root Day in a 20-year span, with the last one being on April 4, 2016.

This May marks the only time a calendar has a Square Root Day in a 20-year span, with the last one being on April 4, 2016.

Square Root Day was founded by Ron Gordon, a teacher in Redwood City. He keeps this website up about the special day. Gordon suggests it's a good day to get things squared away, or go square dancing.

Memorising key square roots and using mental math tricks saves time. Techniques like the nearby perfect square trick and weighted averaging enhance problem-solving skills.

A new DNA computer calculates square roots of perfect squares up to 900. Like quantum computers, DNA computers are a frontier of post-silicon computing.