When calculating numbers, units, hundreds and thousands are arranged vertically, and tens and thousands are arranged horizontally, and adjacent digits are staggered.
The so-called vertical pendulum method is a vertical calculation method 1 and two vertical calculation methods 2, but if it exceeds 5 (including 5), a horizontal calculation method 5 is used (obviously this can save calculation and speed up display and recognition). For example, 7 means that 5 has one horizontal, 2 has two vertical, and together it is 7.
On the hundreds, one vertical position represents 100, two vertical positions represent 200, and one horizontal position represents 500.
The so-called horizontal swing method means that in the positions of tens and thousands, one horizontal chip represents 10( 1000), two horizontal chips represent 20(2000) and one vertical chip represents 50(5000).
Understand?