Quick and accurate mental arithmetic tips make you surprised

Math is a logical and logical science subject, but even so there are many tips to simplify the problem as if it is super hard and troublesome. The logic of mathematics sometimes takes us by surprise!

The numbers all have a specific rule, if we know and remember those rules, the calculation will become "as easy as hand". Historically it has recorded many "holy" mental arithmetic that make the whole world respect.

Alexis Lemaire , "the robot" is known for the world's No. 1 quick mental arithmetic. In 2007, at the Museum of Scientific History in London, England, he calculated the 13th root of a 200-digit number in a record time of 70.2 seconds. To this day, the "divine" calculation of the French man is still a milestone for many people to reach.

In order to achieve that "horrific" achievement, in addition to the "giant" brain with superhuman memory, Alexis Lemaire's quick calculation also plays an extremely important role.

So the quick mental arithmetic of the guy born in 1980 has nothing special, but even the mathematical genius is interesting and admirable. Learn and learn the 9 strange calculation tips below, maybe you will break Alexis Lemaire's record.

With multiplication table of 9