When learning carpentry, it’s very easy to waste a tonne of wood by unskilled use of a saw.
Today’s invention should help.
It consists of an extra, fine-toothed blade which clamps over the normal serrations as shown.
This would be accurately located by alignment with the back edge of the main saw.
It would allow a novice to make smallish saw movements to start the sawing process with a well-placed notch. This would then help the main saw to follow the line created by the guide blade.