9+10=21!! app for iPhone and iPad

"9+10=21!!" is a brain training game for practicing addition.
Are you stupid or smart? Now you can prove it by answering math questions like the kids in the famous vine.
Add up the numbers in the orange box sliding in from the right and compare the total with the number in the black box on the left. Then tap the correct button from the three buttons below!

1. Tap = if the total equals the number in the black box.
2. Tap > if the number in the black box is bigger.
3. Tap < if the number in the black box is smaller.
4. Tap = if the number in the black box is 21 and the number in the other box is 9 + 10.
You will get the bonus points!!
The game gets more difficult as you level up, so it will help you to improve your addition skills!

Choose between Normal Mode and Hard Mode. Hard Mode is extra challenging because the boxes slide in at lightning speed.
"9+10=21!!" is compatible with GameCenter so why not try for the world’s highest score?