Listening to lectures and reading literature on a topic is the most ineffective method of learning. And the one that really works is to teach others and apply the materials you learn in your own life. The famous American professor Edgar Dale knew this back in 1969. He showed the results of his own research in the form of the "Learning Cone" scheme.
On top of it. reading and listening. Thanks to such ways of learning new material, a person can memorize only 10% of what he reads and 20% of what he hears. Watching a video and looking at a picture will help you memorize no more than 30% of what you see.
In the middle of the "Cone of Learning" - Observation of a specific action, demonstration, looking at an exhibit and specimen. These methods will help a person to memorize no more than 50% of what he has heard and seen. And by participating in discussions and speaking, one will be able to memorize up to 70% of what is said and written.
The best way to learn new material is to, imitating, performing real activities or participating in theatrical performances. In this case, you can memorize 90% what is said or written.
If you want to teach your child something, play with him, improvise. Let him or her be in the circumstances you suggest. For example, a game of store will help to teach addition and subtraction.