Ebi-kun had been working with the trinominal cube this week, he hasn't shown much interest in it for quite a while so I was surprised that he took it out. I gave him the presentation again then left him to it. I was busy cutting out and I could hear him talking to himself, he was rather amusing. "I love doing this, this is fun" and a bit later "this is stupid, I am not doing this again" but he wouldn't give up and later still "I did it! I can do it, it isn't so difficult really". He didn't know I could hear him so he came over to give me a hug and tell me he had finished.
If you want to know what the trinominal cube is all about, there is a lecture here, the video quality is pretty poor though.