You can find it by searching Gauss Mathematics on Wanli Travel, and it is free to watch.

Mathematical animation suitable for children: digital bug, suitable for children aged 1-6; Digital building blocks, 2-6 years old can simply add and subtract; Little brothers and sisters in Math City, aged 2-8, let children learn to count, shape and spatial relationship when solving problems; Little pioneer in mathematics, 6- 10 years old.