How to play Adding Aliens 

The first thing you must do when playing Adding Aliens is pick a difficulty level. The Beginner difficulty is for kids who are new to addition and need a version of the game with a slower pace and can only handle adding together small numbers. Intermediate is for more players that can add two digit numbers, but not necessarily quickly. The Advanced difficulty is for players that can add multi-digit numbers together fairly quickly. Impossible is for adults and kids that are very good at adding numbers together in their head very quickly and would like to test their skills against a very challenging version of the game.

When you start to play, aliens will descend from the top of the game screen with an addition problem positioned above them. In order to destroy the alien you must type an answer to the addition problem on your keyboard. If you are correct, the alien will be destroyed and you will gain in points. The number of aliens that are remaining in the level will also be reduced by 1.

As soon as you type an incorrect digit, you will get an error message, and you will need to start typing the number again from the beginning.