Hi Amom!
Yes, Little Math does come with a Chinese (Mandarin) sound set in a female voice. You may want to check the forum's LM library in case you want to download another Chinese sound set, or you can record your own sound set too (you can access the Easy Voice Recorder in LR from your Start menu).
You can use LM's Override function to quickly make all lessons play the Chinese sound set instead of the default English one. Here are some articles that you can refer to:
Since he first learned math in Chinese, the confusion will likely happen only at the start -- eventually your son will understand that you're teaching the same number and math concepts in a new language. If you do plan to teach him English as well, then this shouldn't be a big problem.
About the lessons, Little Math actually shows different icons in every lesson. Most lessons are set to use a random icon from the default icon sets included in Little Math (Basic Shapes, Fruits, Toys, etc.) so you can be sure that instead of the usual red dots, your son will see something else everytime you play a lesson (even if the lesson teaches something that he already knows). Just like what I mentioned about sound sets above, you can also download or create your own icon sets if you like.
You may try previewing a lesson first to see if you can just skip it or still play it as a review for your son:
- Go to LM's Playback > Courses screen
- Open the lesson or session folder you want to check
- Select a lesson, and you'll see a preset preview for it on the right side of the screen (or you can play it without your son around just to check)
I hope this helps!