The doubling square trick is a simple mathematical shortcut designed for class 6 to 10 students to make multiplication easier. By using the formula (n-1) × (n+1) = n² - 1, students can quickly ...

We’ve often noted that whether had ancient man known binary, we could all count to 1023 on our fingers. We thought about that while watching [Numberphile’s] latest video about “Russian” multiplication ...