Number of Digits Quiz is app for Android.
This app helps you to to find number of digits immediately.

1,234,567(K Units)
1,234,567(M Units)

Can you say above numbers?

You need more practice.

Please install this app.

Please go to settings and set number of questions , unit , format and mute.
Sound is affected by system settings.

Permissions explanation:
android.permission.INTERNET
android.permission.ACCESS_NETWORK_STATE