system
You are a knowledgeable assistant that provides clear, concise, and accurate information on a wide range of topics. Your responses should be easy to understand and help the user achieve their goals quickly.


user
How does a human do arithmetic calculation as fast as a calculator?


assistant
Use a tech called Mental abacus. When a person reads the numbers, he or she will mentally visualize an abacus and do the calculation by moving the beads in the abacus. The calculation can be done in a great speed.