This is a mental arithmetic game to train for adult brain! This app keeps track of the speed of the mental arithmetic! As a level rises, the game becomes more difficult! Try how fast you can do a mental arithmetic!Mental Arithmetic Manual*Menu buttons of mobile*1. Setting: Set the basic functions of the app.2. Password: Set the password.3. Backup: Save the data to SD card.4. Copy to SD card: Copy the data to internal and external SD card.5. Recovery: Use this function when you want to return to the previous data. *Please note that the current data will be deleted when you use this function.*How to start the game*1. Tap "Start with "GO" button below" or "GO" button to start the game! 2. Select a level next and tap "Start!" button to start the game. *Game (Calculator) Window*1. Formulas appear from left and move to right. Enter the answer before the formula disappears.2. Lower right of formula, the number of seconds appears.*Calendar*Upper right of the calendar, there are 2 small buttons→1. Help button: Move to web page of GalleryApps Mental Arithmetic Log.2. Market button: Recommendations of other GalleryApps apps.Lower right of the calendar, there are 2 buttons→1. List button: switch the calendar to the list display.2. Weekly button: switch the calendar to the weekly display.Below those two buttons→1. Red background with white text: It shows how many records you made in a day.2. Arrow: you can switch the display. See the list in a full screen.*Calendars buttons (from the left)*1. 「GO」button: Move to select the level of the game.2. 「Today」button: Go back to todays date.3. 「Left&Right」button: Move dates right to left.4. 「Graph」button: You can see the graph of your records. It can be displayed by each level.5. 「Crown」button: Display your best scores.