算术小游戏-数学加减乘除 is a free iPhone game developed by 阿强 李. This game consists of five different types of arithmetic challenges, each with varying levels of difficulty. Each question is accompanied by a countdown timer, and if the time runs out before an answer is selected, the player fails. The game's difficulty increases as the number of questions answered correctly increases.

The five types of challenges in the game are as follows:

1. Multiple Choice: The player is presented with three options and must select the correct answer to the arithmetic equation displayed.

2. True or False: The player must determine whether the arithmetic equation displayed is true or false by clicking on the corresponding checkmark (√) for true or the cross (×) for false.

3. Double Questions: An advanced version of the true or false challenge, where the player must determine if both arithmetic equations displayed are correct. If either equation is incorrect, the player fails the question.

4. Mixed Questions: Randomly presents either a true or false question or a multiple-choice question.

5. Easy Questions: Similar to the mixed questions, but with extended countdown time and no increase in difficulty as the number of questions increases.

After each failed attempt, the player's total score is submitted to the leaderboard, allowing them to gauge their own skill level.