How did you get it to 28? 9+((120–21·3+10-4)·2:3-(6·9-(80–18·4)·4)+18):2 = 9+((63)*2:3-(54-(8)*4)+18):2 = 9+(126:3-(22)+18):2 = 9+(126:-1):2 = 9+(-126):2 = -117:2 = -58.5 ???

Potatis: In your third>fourth segment, you do subtraction/addition before division. 9+(126:3-(22)+18):2 = 9+(126:- 1):2 should be 9+(126:3-(22)+18):2 = 9+(42-22+18):2

I got 28 in my brain after a little while. I'll note that this is the first time I've seen dots and colons used for multiplication and division. Is that common?

In my experience, dots for multiplication is common, colons for division is not. Colons are used for ratios which represent relative proportions, rather than an operation with a single answer.

Well, as I said, I've never seen colons used for division at all. I don't know about this switching order of operations malarkey though. Sounds like something that would ruin the very foundations of mathematics as we know it!

In my country, we use dots for multiplication and colons for subdivision. Nobody uses × or ÷ here. Though in my country, we just prefer using fractions instead of colons (starting from 6th grade or so), so we don't run into colons that often anyway.

9+((120–21·3+10-4)·2:3-(6·9-(80–18·4)·4)+18):2 = 9+((63)*2:3-(54-(8)*4)+18):2 = 9+(126:3-(22)+18):2 = 9+(126:-1):2 = 9+(-126):2 = -117:2 = -58.5 ???

Is Admer the only one that didn't cheat like Pengy and got the right one?

You lazy Pengy...

`9+(126:3-(22)+18):2 = 9+(126:- 1):2`

should be`9+(126:3-(22)+18):2 = 9+(42-22+18):2`

I got 28 in my brain after a little while. I'll note that this is the first time I've seen dots and colons used for multiplication and division. Is that common?

Nobody uses × or ÷ here.

Though in my country, we just prefer using fractions instead of colons (starting from 6th grade or so), so we don't run into colons that often anyway.

I turned 46 in October.