The Innocence of Children

My daughter wanted to go out and play. But the adults said she couldn't go out because she hadn't finished her homework. So she started crying. I spent 20 minutes comforting her and started guiding her. What are the pros and cons of spending time crying and being sad versus spending time doing homework to persuade them to go out? At first, she seemed to understand a little, but when she actually finished her homework and got the reward of going to the park, she realized that crying doesn't change the situation, but doing things does. I hope this experience will teach her that it's okay to cry to vent when she's sad, but the key is how to achieve her goals after crying.