When UU is crying or angry. Several cases maybe he meets.

First one, he is hungry.

Second, he pees.

Third, he is sleepy.

Fourth, he is in bad mood.

So, a secret method, except for mother-milk, baby bottle, changing diaper, easing him to sleep, is to let him to stand by assistance of adults. In that way, he will be happy again, and can play very well.