People can easily remember 3 or 4 things in their working memory as long as they are not distracted.
Diapositiva 3
Phone numbers chunk 3 or 4 numbers together to make it easier to remember; remembering 10 separate numbers is harder than remembering 3 chunks, each containing 3 or 4 numbers.
Diapositiva 4
If you are expecting people to remember more than four things, then chunk these things into categories to make it easier for them.