YouTube videos are great for sharing the wonders of science and mathematics to the general public. However, it takes special tricks to express such technical topics successfully in video format. The Finnish science YouTube channel “Samun tiedekanava” achieves this using three principles. (1) The digital world runs on mathematical algorithms, for example Instagram filters. This way everyday life can be connected to math. (2) A video should have one key scientific idea, which is carefully popularised and visualised. The science needs to be simplified while retaining the core insight. Animations are made using the actual scientific formulas and software; this is where a scientist can offer something that is often impractical for a science journalist to produce. (3) There are real scientists shown, including women, promoting the message that science is for everyone.