This app can generate formulas and train as many times as you want to do abacus. The app will display the formula and the user can use the abacus to calculate, multiply and divide as many times as they like. lines can specify the number of number calculations.
This app is not recommended as decimal point calculation is misleading.
Ver, 1. cannot be upgraded because the key to update was deleted by mistake.
Since the division of Create for the Abacus ver, 2. is not completed, the application of ver, 1. can use the natural number function of division in particular, so please use it together with ver, 2. which has the incomplete division function. Please wait until ver, 2. is completely updated. When ver, 2. is completed, we recommend that users switch to ver, 2. ver, 2 is here. https://play.google.com/store/apps/details?id=wbxhb399.jp.geocities.abacus
I'm very sorry for this situation.