|This means one beer in Finland.|
Then you give the money and walk away, or if you have a bank card you show that you are going to pay wit ha card, press your pin code and walk away. You can also show "no" with your hand if you don't want the receipt. If you want receipt you can pass your hand towards the bartender or just show "yes" putting your thumb up. If you want to thank, you can just bend your head a bit down and up.
Imagine, this is how people really do. I don't say this is very polite, but it's how you can survive through a social situation without saying a word.