How can I teach my child to budget and manage their allowance effectively?

I totally get where you're coming from - teaching kids about budgeting can be tough, but it's such an important life skill. I think the issue might be that a spreadsheet can be a bit dry for a 10-year-old, so you might want to try making it more interactive and fun. You could try using a clear jar or envelope system where they can see their money being divided into different categories, like saving, spending, and giving.

This visual approach can really help them understand where their money is going and make it more tangible. As for autonomy, I think it's great that you're considering giving them some freedom to make their own financial decisions - it's all about finding a balance between guiding them and letting them learn from their own mistakes. You could start by giving them a small amount of autonomy and gradually increasing it as they get more comfortable with making smart financial choices.

Another idea might be to set some short-term goals with them, like saving up for a specific toy or experience, and help them work towards achieving it. This can help them see the value of saving and budgeting, and give them a sense of accomplishment when they reach their goal. Just be sure to have open and honest conversations with them about money and budgeting, and be patient - it's a process, and it might take some time for them to get the hang of it.

Overall, I think you're on the right track by trying to make budgeting fun and engaging for your child, and with a little creativity and patience, I'm sure they'll develop healthy financial habits that will serve them well in the long run. Good luck, and I hope you see some progress soon!