Normally Japanese is the same way—numbers after 10 are just the single digits combined, making it is normally easier. The strange pronunciations of this song are unique. But they do seem to work—math is often a very strong subject of nearly everyone here.
I'll have to look up one of the Cantonese videos! I'm curious how that one sounds.
I think in general Asians are very strong in maths - and I notice you said math, another interesting cultural difference 😉
Here's a video in Cantonese if you're interested
Haha math/maths is a long long debate in US/UK English, like color/colour, etc. My friends who use UK English are always accusing me of not knowing real English.
Interesting video! It sounds strange to me, but of course I am used to the Japan version so that's why.