Why 2025 is called a perfect square year [Video]

Mathematicians aren’t just ringing in 2025, they’re also celebrating the start of a perfect square year.

“A perfect square is what you get when you take a counting number – 1, 2, 3, 4, etc. – and multiply it by itself,” explained Craig S. Kaplan, a professor in the school of computer science at the University of Waterloo. “The first few perfect squares are 1 [1×1=1], and then 2×2=4, and 3×3=9, 4×4=16, and so on.”

When you multiply 45 by 45, you get 2,025.

“It is a perfect square year and they are arguably interesting because they are relatively rare,” Kaplan added.

The last perfect square year would have been 1936, as 44×44=1,936, and we’ll have to wait until 2116 for the next one.

Kaplan’s work primarily focuses on the interaction between mathematics and art. He also made it onto TIME’s Best Inventions of 2023 list for helping discover an “einstein” – a mathematical problem that was considered impossible …