I remember that too CD, we called it french knitting. 

As astro said you can buy a gadget to do it, think it is called a knitting dolly or something, I actually bought my twin grandaughters one each last year, they did have a go but I dont think they mastered it. Dont think it was fun enough for them TBH xx

https://www.bing.com/videos/search?q=french+knitting&view=detail&mid=59FEA80077BC2C289CE259FEA80077B...