The study of abacus mental arithmetic begins with the study of abacus. Most of us adults can do abacus calculations, but we can't practice mental arithmetic. The main reason is that we have passed the stage of active thinking in images. Before the age of 65,438+02, we thought in images. After the age of 65,438+02, we will use logical thinking instead of image thinking. An abacus is a concrete object with color, size and shape in a child's mind. In the eyes of adults, it is an abacus. What color, shape, size, etc. There may be no detailed description and overall description.
Abacus mental arithmetic is that children form an abacus in their own minds. When a child is counting, it becomes mental arithmetic by using the abacus in his head.
Because when learning abacus mental arithmetic, the first thing to learn is listening and calculating, which also trains children's listening-memory and image memory. Of course, the most important thing is to improve the calculation speed.
The way to quickly calculate numbers with fingers is to use five fingers of the left hand as the number dial, each finger represents a number, and five fingers can represent five numbers: one, ten, hundred, thousand and ten thousand.
The number on each finger is 9. First, we see three joints on our fingers. From top to bottom, the left side of the first joint stands for 1, the left side of the second joint stands for 2, and the left side of the third joint stands for 3. From 3 to 4, the upper end of the finger stands for 5, the pulp of the finger stands for 6, and there are three horizontal bars on the palm. From top to bottom, the first bar represents 7 and the second bar represents 7.
The calculation method of finger fast calculation is a method to reproduce the calculation process of finger by using brain images and mental arithmetic and get the results. It regards the left hand as a virtual abacus with five gears, and counts with the right hand according to this abacus. When counting, point the fingers of your left hand with the fingers of your right hand.
Its clear division of labor is: right thumb/left thumb, right index finger, left middle finger, right ring finger, left ring finger and right little finger. The corresponding professional division of labor does not interfere with each other. Which finger is clicked, which finger is extended, and which finger is not clicked, bending, indicating 0. You can perform four operations of addition, subtraction, multiplication and division of any number within100000 bits.
The first step in learning the fast finger algorithm is to know your own hands. In order to attract children's attention, let children play finger games first, palms inward, five fingers straight, let children observe their thumbs up alone. Next, remind the child that the left hand represents ten digits, the right hand represents one digit, the thumb represents five digits, and the other four fingers represent 1. On the basis of thumb, the index finger, middle finger, ring finger and little finger represent six, seven, eight and nine respectively, so that the five fingers can represent the number nine.
When the right hand is more than nine, it will be closed with five fingers to indicate 0, and the left index finger represents 10, which is a decimal. This repetitive cycle represents every number from 0 to 99. With the help of your foot movement, you can represent a hundred numbers within 300. When teaching young children, we must repeatedly emphasize that "the left hand is ten and the right hand is one". And use the finger positioning formula to help children distinguish.