My son draw circuits by a pencil, which is not beautiful at all as Figure 1. We found a way to draw a good and perfect EasyEDA.com, we can do circuit simulation, PCB design, Electronic circuit design online for free. It works well on Mac, Linux, Windows and Android: All Platforms Supported
EasyEDA is a free, zero-install, Web and Cloud-based EDA tool suite, integrating powerful schematic capture, mixed-mode circuit simulator and PCB layout in a seamless cross-platform browser environment, for electronic engineers, educators, students and hobbyists.
Please read more on easyeda.com look below:
Now he want to draw the circuit on firefox browser on Ubuntu OS platform.
It is very easy to use Even my son was 10 years old also can use them.
He learned it by myself.
We will explain it briefly. Because we think that is similar to a typical circuit design software.
First of all , we need to register at easyeda.com.
We believe that you can do, good luck.