The author correctly says 'pieces of lego' into the cup - but previously says 'playing with their legos'. I'm sure they wouldn't say 'the children were looking at the sheeps', and then later on say 'the children counted the sheep'.
For whatever reason, this irks me when reading as a grammar error. It's like a klaxxon sounding in the middle of the sentence.
I know what you're saying, and the funny thing is that when I wrote that, I actually paused and thought about the proper way of referring to LEGO. So if you google "playing with legos" there's a ton of articles that use that expression, such as this one on HuffPost for example: http://www.huffingtonpost.com/2014/01/28/google-legos_n_4681...
So kids 'playing with their legos' is valid given the fact that LEGO has become a household name and LEGO can refer to the brand, the game itself, while Legos, or legos can refer to the LEGO blocks themselves. It's sort of like using Google as a verb (http://en.wikipedia.org/wiki/Google_(verb))
Thanks for reading btw
PS. English is my third language so a grammatical error here and there wouldn't be that bad anyways :)
Most North Americans will have been brought up with the incorrect usage, and will defend it strenuously, but they are wrong. The correct plural is Lego, or, if you want to get specific (as you did in the article), lego pieces or lego bricks. The company spent many years trying to teach correct usage but gave up in the end. But correct is still correct, and if english isn't your first language, there is still time!
Even in the verb usage 'kids playing with their lego' - you don't pluralize the term.
For whatever reason, this irks me when reading as a grammar error. It's like a klaxxon sounding in the middle of the sentence.