A.Sugi is the developer of the tool which is related to the Educational category. This application has been downloaded and set up by over 100 users and its latest update is dated Mar 31, 2013. Download the setup package of 計算ドリル4 1.0 that is completely free and have a look at users' reviews on Droid Informer. The app runs flawlessly on Android 1.5 and above.
It's safe to download the app.