Student loan calculator
Entertaining account about the stock market, flash trading, flash crash, and not to trust people with your money - how one guy made $50 million and lost it to scams:
https://www.youtube.com/watch?v=_ZDEWVJan0s
On the excellent Bloomberg Quicktake YouTube channel.
This guy looks like a stoner, but is actually legit at spotting and explaining stock market trends: Financial Education YouTube channel.
https://www.bankrate.com/retirement/calculators/social-security-benefits-calculator - Better than the official SocialSecurity Gov website calculator. Estimate how much money you'll get when you retire. See it in today's dollars, or accounting for inflation, how much you'll make in future dollars.