Whether your four-year-old is working on a hard puzzle, or your fourth grader is struggling through math homework, when they ask for your help, start by asking them how they would like to be helped. If you swoop in and give them your brand of helping, you may be doing too much, which discourages independent problem solving or frustrating the system.
I learned this the hard way. When my older daughter was learning to read, she asked me to please just give her the word when she got stuck. I explained that, if I just gave her the word, she wouldn’t learn how to best sound out words on her own. Her valid point back was that when she was reading and had to stop to sound out words, she would lose the storyline and be confused going forward. She also said she was getting plenty of practice sounding out new words at school, thank you very much. So, I started just giving her the words when she was stuck. This lasted a few months as she was gaining skills at school and then it tapered off.
When my younger daughter was learning to read, and she would get stuck on a word, I just gave it to her. We went on like this for the first several months. One day after I gave her a word, she stopped and said, “please stop doing that! If you keep giving me the words when I am stuck, I will never learn how to read them myself.” She was right, I was slowing her progress and should have asked her how she wanted to be helped.
Soon after they are old enough to ask for help, they are likely old enough to explain how they would like to be helped.