one digit addition 2.1

This App "one digit +" is one digit addition training App. And this is a search game and speed puzzle game, too. There are 9 questions on nine stages, random 81 questions from "1 + 1 = 2" to "9 + 9 = 18".

This is a Lite version of "one digit +-x÷". The paid full version has four categories. Addition:"one digit + ", subtraction:"one digit - ", multiplication:"one digit x " and division:"one digit ÷ ".