What is the practice of abacus?

Abacus addition method, subtraction practice methods have to play  hundred, three into, nine disk clear, hundred sub-map, etc .; abacus  multiplication, division of the practice method has a lion roll  hydrangea, Phoenix wings and so on.


Hit one hundred: abacus arithmetic practice with one of the topics. From 1 to 100, the result is 5050.

Three discs: one of the topics used in the calculation of abacus. In  the abacus dial 123456789, and then from the high to the low, see a few  plus a few (that is, according to the number of the file, plus the  original number of doubles), so for three consecutive, the last plus 9,  the result is 987654321. "Three into a" also known as "three clear", also known as "three back".

Nine disk clear: abacus plus, subtraction exercises one. Dial 123456789 on the abacus. And then add nine times 123456789. The result is 1234567890. And then nine consecutive minus 123456789, and finally had 123456789. "Nine disk" also called "nine into".

Figure  1: 100 to 100, respectively, fill in a hundred square meters and  drawings (see Figure), each of its rampage and each vertical line on the  number of 10 and are equal to 505, The sum of 10 lines is 5050. This picture is called "one hundred figure". Can be used for abacus plus, subtraction practice.

Phoenix wings: multiply with 16225679 by 35, draw 567898765.

In the abacus, 567898765 this number has the image of the wings.

Lion roll hydrangea: This is the traditional interesting multi-digit multiplication, division exercises.

Because: 5 �� 2 = 10

52 �� 22 = 102

53 �� 23 = 103

...

59 �� 29 = 109

While 59 = 1953125

29 = 512

109 = 1000000000 (ie 1 billion)

That is: 1953125 �� 512 = 1000000000

1953125 this number dial on the abacus is like a lion, multiplied by 512, the number of 1000000000. This is a count on the abacus is only a bead by the beam, people vividly called it "Hydrangea".

You can also use the inverse operation relationship, 1000000000 divided by 512, get to 1953125. In this way, and practice the division.