1, the left hand represents ten digits, the right hand represents the unit, 2, the big finger represents five (equivalent to the upper bead of the abacus), and the other four fingers represent 1 (equivalent to the lower bead of the abacus), 3, break five, add and subtract (4+3)A, apply for four fingers (not big fingers) b, apply for big fingers, and take off the tail. If the ring finger (2 fingers 5-3) adds 1(4 fingers 5- 1)4, the ring finger is broken 10 plus or minus (4+7)A, the right hand applies for 4 fingers (not thumb) b, the left hand adds 1 finger, and the right hand receives 3 (.

Quick mental arithmetic is not abacus mental arithmetic/palm mental arithmetic. You can quickly write the correct answer by reading the questions without any auxiliary tools (such as abacus/fingers). Fast heart is a fast calculation method that is consistent with the primary school mathematics calculation method, but simpler than the primary school textbook. Easy to learn, can really reduce the burden on children.

Fast mental arithmetic —— (mental arithmetic, oral arithmetic and written arithmetic) is a teaching mode that is really synchronized with primary school mathematics textbooks. Fast heart is the only way to perform simple operations without any physical objects, neither abacus nor fingers.