SoloBang! 〜Enhance your brain〜

Japanese soroban is an abacus since 1600s.
Despite the popularity of modern calculators, sorobans are still used today.
It is said that by using soroban, you will automatically become adept at mental calculation.
In this app "Solobang!", I redesigned the Japanese soroban to fit more on smartphones.
The basic methods of operations are the same, but you touch the circles instead of flicking the beads.
The number is limited to 6 digits at max to make it suitable on your smartphones.

-Calculate!

This is where you can use the Japanese soroban features.
The circles in the lower screen is the beads and when you touch them the number cooperates will show on the display area above.
Try setting numbers freely to get used to Solobang.
You can use it as a calculator too.

-Challenge!

Ten questions will be displayed randomly for each levels.
You will be able to earn stars by answering to questions in certain time frames.
Try and find out how many stars you will be able to earn.
Level1:Setting numbers[Free]
Level2:One digit addition[Free]
Level3:Two digit addition[Premium]
Level4:Three digit addition[Premium]
Level5:One digit subtraction[Premium]
Level6:Two digit subtraction[Premium]
Level7:Three digit subtraction[Premium]

You can challenge Level 3 and above by purchasing the Premium version.