Use APKPure App
Get Whats Nine plus Ten Calculator old version APK for Android
It can do Substractions, Multiplications and 9+10 !
Test it yourself!
9+10=21, you stoupid ?
Funny Calculator that can do regular Maths until you type 9 + 10! A surprise is waiting for you!
The vine where it all started:
https://vine.co/v/M3nFivVTq7Y