Abacus is an ancient calculating tool that can be used for various mathematical calculations like addition, subtraction, multiplication, division or even for basic counting. The design of this tool ...

Ever dreamt of solving math problems in your head with the speed of a calculator? Mental math might seem challenging, but it's a skill attainable through the right tools and techniques. The abacus, an ...

FORT LEE — For 10 seconds, a series of 50 random three-digit numbers flashed on the screen. After another second, abacus master Jeonghee Lee announced she'd finished the mental addition, correctly ...