The big circle of the stopwatch is seconds, and the small circle is minutes. If the big circle is 30 squares (30 is written on it, there may be 60 squares, indicating that the accuracy is half a second), and one minute in the small circle is divided into two squares, you can read a complete few minutes. If you pass a small square, you can add half a minute to the great circle second. If you fail, you can watch the big circle seconds directly.

Composition of stopwatch:

It is timed by controlling the rotation of the pointer by using the isochronism of the pendulum. It has a large dial on the front and a small dial on it. The second hand rotates along the big dial and the minute hand rotates along the small dial. The total time indicated by the minute hand and the second hand is the time interval of measurement. There is a watch handle directly above the watch with a button on it. Turn the button and wind it up. This is the power of stopwatch movement.