Freerice.com is a website run by the World Food Programme, an organization run by the United Nations to help fight world hunger. On this site are simple questions (say for example, vocabulary questions) where for every question you get correct, they donate 10 grains of rice to help feed the hungry. They have multiple categories of questions such as basic math, foreign languages, human anatomy, and geography.
It's an excellent way to take part in helping a good cause even if you don't have the money to donate directly. You can do it passively while browsing your computer, playing video games, or ****posting on here. I've already donated 1050 grains of rice and while that's relatively small (a full cup of rice is 5k-10k grains), I have no intentions of stopping.
Even if you don't know the answer and get it wrong, it'll tell you the answer, and then repeat the question shortly after so you can get it right and be able to donate another 10 grains. It's simple and easy and for a good cause. I highly recommend checking it out.
Quick note: Consider disabling adblock on this site as well, as the ads are what pays for the rice that's donated. It's probably the only site I've willingly disabled adblock for.