It’s an old video but always a good one. I’m sort of like the guy on the bike because especially when I was first learning Danish, I tried just grunting at people in hopes they wouldn’t notice the words missing from my sentences. (I’m pretty sure people thought I was just crazy.)
And at 3:36, this is basically what I did in shops for years. I could never really count above 40 because the words for the numbers completely stop making sense to me at that point, so I too would just hold out a clump of money or just used my Dankort while pretending I knew what the total was. I was extremely lucky that as far as I know, I never got ripped off.