Counting fingers is the same as calculating with a wrench. Counting fingers is a simple mathematical calculation method through fingers, which is generally suitable for students in lower grades of primary schools. For example, put two fingers together to represent the number 2, then bend the other fingers to represent the numbers 3, 4 and 5 in turn, and then add these fingers to get the result of 5+4+3= 12. Wrench finger calculation method is a quick mental calculation method through fingers, which is suitable for most people. This method uses fingers to correspond to numbers, and then adds and subtracts, which can get the result quickly. For example, the numbers 1 and 2 correspond to the index finger and middle finger of the left hand, and the numbers 3 and 4 correspond to the index finger and middle finger of the right hand, and then the corresponding fingers are bent to indicate addend or subtraction, and finally the result is obtained by calculating the bent hand index. Finger calculation of pipe number and wrench finger calculation are two different calculation methods, but both help people to carry out simple mathematical calculation through the corresponding relationship between fingers and numbers. Therefore, there are some similarities in their way of thinking.