for 2 to 4 players, using no equipment
This is an ideal game to play in the car on a trip with kids.
(Didn't learn the pseudonumerals?  Learn to pseudospell now!)

In Numberwords, each player in turn thinks of a word -- usually a name that all the players know, or the name of an object that all the players can see in the room where they are playing.  He does not say the word, but only says the numbers that pseudospell that word, and the other(s) try to guess the word.   If no one guesses the word, the original player tells the word and then says a new number before giving up his turn.

When two people play, it is fun to simply take turns without a point system. With more than two players, the one who first succeeds in guessing the word gets a point, and each player remembers his own score.

With young children it is best to use the names of their friends and classmates.
Here are examples:
  Player A says "3412" and the other players try to guess the name Martin
  Player B says "74012" and the other players try to guess the name Christina
  Player C says "2140" and the other players try to guess the name Andreas
  Player A says "5091" and the other players try to guess the name Elizabeth

With older children, it is fun to choose a category, such as the names of
celebrities, presidents, countries, cities, brand names, professional sports teams, etc.

More examples:
For Presidents:
  Player A says "5272" and the other players try to guess the name Lincoln
  Player B says "40851" and the other players try to guess the name Roosevelt
  Player C says "75212" and the other players try to guess the name Clinton
  Player A says "646 6212" and the other players try to guess the name George Washington

For Countries:
  Player A says "30397" and the other players try to guess the name Mozambique
  Player B says "3707" and the other players try to guess the name Mexico
  Player C says "692" and the other players try to guess the name Japan
  Player A says "5703947" and the other players try to guess the name Luxembourg