Whoever is slow to anger has great understanding, but he who has a hasty temper exalts folly. - Proverbs 14:29
Every parent should have this verse seared in their mind. Raising kids is great, but it's also very trying at times. It is for those times that God gives us this directive. I have a great father, and I believe he exemplifies living this verse out. I have seen my dad mad, but I did not live in a house filled with yelling.
Yelling is easy, but not effective. As a parent, I disappoint myself when I yell. Kids need discipline, and there are plenty of times for that, but it's important to be of gentle spirit, even in discipline.
Slow to anger has many applications outside of just parenting as well. Our world expects anger, and when we are kind it often takes people by surprise. I'm always amazed at how anxious customer service people get when things go wrong. Those poor people must get chewed out day in day out. Life would be a lot less stressful if people would relax and look for understanding instead of anger.
Maybe Bill & Ted had it right with their motto. "Be Excellent to Each Other"
Not bad advice, when you think about it.