Rational methods of oral calculations (4-11 cells)

Direction: mathematical
Work form: problematic - search engine

Purpose:
Study rational methods of computing, for the production of which oral counting or the use of pencil and paper is sufficient, help yourself and your comrades master computing skills perfectly, developing memory and attention. Tasks:

1. Get acquainted with the method of high-speed calculation by Yakov Trachtenberg;
2. Study the technique of cross multiplication under action with two-digit numbers;
3. Get acquainted with other interesting techniques of oral computing.

The presentation contains 11 slides (188 Kb)