How to use the seven-bead abacus
Question 2: When calculating with a seven-bead abacus, how to dial the beads better? In order to make abacus calculation correct and fast, we should not only master four calculation methods, but also pay attention to fingering, that is, the division of fingers and the method of dialing beads during abacus calculation. When using the seven-bead abacus, you usually use the thumb, index finger and middle finger of your right hand to dial the beads in coordination. The division of labor between the three fingers is: thumb: dial the bead up. Index finger: Pull down the bead. Middle finger: move the upper bead up and down. The ring finger and the little finger should naturally bend to the palm of your hand to avoid touching the abacus. When the "lower bead" is dialed upward and the "upper bead" is dialed downward, you can dial it with your thumb and middle finger at the same time. When the "lower bead" is dialed downwards and the "upper bead" is dialed upwards, you can dial the middle finger and the index finger at the same time. When both the upper bead and the lower bead need to be pulled down, generally, the upper bead should be pulled down against the beam first, and then the lower bead should be pulled off the beam. If the "lower beads" are all off the beam, you can also dial the middle finger and the index finger at the same time. When it is necessary to push the "upper bead" and "lower bead" upward, generally, the upper bead should be pushed against the beam first, and then the upper bead should be pushed away from the beam. You can also dial with your thumb and middle finger at the same time. When calculating the abacus, you should first clear it, that is, dial the beads against the box first, and then dial them in numerical order from the high position. Commonly used terms are: up and down: it means to lean the beads against the beam. If you dial 2, 5 (or 5) and 6. Go: It means to lean the beads against the border. If you dial 2, 5 and 6. Enter one: it means 1 before dialing one digit. Last one: indicates the previous one 1. In addition: used with "Back" to indicate that the remainder is set in this file.
Question 3: Who has the abacus formula? The five-bead formula and the seven-bead abacus formula are basically the same, and the top bead and the bottom bead are not used. It can only be used when calculating division with reduced division formula. At present, quotient division is basically used to calculate the division problem.
In fact, the five-bead abacus is a simplified abacus to improve the frequency of dialing beads, which removes the upper and lower beads that are no longer used in the seven-bead abacus.
Therefore, the current five-bead formula is completely applicable to seven beads.
Question 4: Why did someone find five-bead abacus and seven-bead abacus in ancient times? According to historical records, China had invented and used the five-bead abacus before the Eastern Han Dynasty. According to the Notes on Numerology written by Xu Yue, a mathematician in the Eastern Han Dynasty, from A.D. 196 to 2006, it is recorded that "abacus calculation: controlling the four seasons, gaining three talents in latitude and longitude". Northern Zhou mathematician Zhen Luan's note: "The inscription is divided into three parts, each with five beads. The upper bead is different from the lower four beads. There are five upper beads with different colors and one lower four beads. " It can be seen that the abacus in the five beads at that time was not an abacus that penetrated the beads-there was no hole (no file) on the beads, so it was called a bead plate and a dish bead. At that time, beads painted with different colors were placed on a wooden board engraved with rows of longitudinal arc grooves.
Question 5: Which is more suitable for beginners, the 7-bead abacus or the 5-bead abacus? Five beads
Question 6: Use seven beads on the abacus, with three digits at most and three digits at least. Maximum 960.
Minimum: 1 19
think
Because the topic is limited to three digits, in order to maximize the number, there should be as many beads in the advanced file as possible, and at most five beads (upper 1, lower 4) can be placed in the hundred places to represent 900. At this time, there are still two beads left, both of which are placed in the tenth place (upper 1, lower 1) to represent 60; To find the smallest three digits, first put a bead on the 100th digit to ensure that it is three digits (upper 0, lower 1), which means 100. In order to reduce the number as much as possible, there should be as many beads in the low-order number as possible, and each number can put up to 5 beads (up 1, down 4), which means 9. At this time, the tenth digit still has 1 bead.
Question 7: What is the function of the top row of beads in the seven-bead abacus? Thank you! ! In the multiplication and division algorithm of China's traditional abacus, the upper and lower beads can be used, and they must be used in some large multiplication and division operations. Even the beads are not enough, so we have to pause. This time is called "hanging beads". The top bead hanging beads represent 10, and the bottom bead hanging beads represent 5. The traditional algorithm can be used to calculate 9999 times 9999 on the abacus.
Question 8: The appearance and structure of the seven-bead abacus.
The existing abacus has different shapes and materials. Generally, abacus is made of wood (or plastic). The abacus is composed of a string of equal number of beads arranged in a rectangular wooden frame, and a beam divides the beads into upper and lower parts. Counting beads run through a straight column, commonly known as "gear", which is generally 9, 1 1 or 15. There is a beam in the middle of the file with two beads (1 bead for accounting, 5 for each bead; 5 beads under the beam (4 beads accounting), each bead is 1. Abacus is called abacus, and abacus has corresponding rules for four operations, which are collectively called abacus rules. Compared with general operation, skilled abacus calculation is not inferior to calculator, especially addition and subtraction. When in use, you can dial the abacus up and down according to the mouth shape to calculate. Abacus is simple and quick, and is widely used in shops in China.
Question 9: Why did the seven-bead abacus first become a traditional calculation tool in China? It is one of the important heritages in China's cultural treasure house, and some people abroad regard it as "the fifth great invention of China". At present, the State Council has included abacus in the second batch of national intangible cultural heritage list.
Generally, the ancient abacus has seven beads in each file and two beads on the beam, each representing five; There are five under the beam, each representing one. "Pull out the beads casually, and there will be an answer", "When the beads move, there will be a number".
With the popularization of decimal system, the new abacus is generally one bead on the beam and four beads on the beam, which is convenient for calculation and use. But when people mention abacus in daily life, the first thing that comes to mind is the bright red abacus. Seven big maroon beads crossed the celestial bodies. Make Gan Kun clear!