As'salamu Alaikum everyone,
Checkout this youtube video of "Arabs got talent". Now while it's in Arabic, the test that the 8-year old Palestinian boy, Muhammad Al-Juyoosy محمد الجيوسي, was in English:
https://www.youtube.com/watch?v=C_m48vHp_x8 Start from minute 1:44.
He was given a very long arithmetic formula with so many numbers of adding and subtracting, and he got the answer right.
Take care
,
Osama Abdallah