Brain Test Level 552: Crack the code.
Brain Test Level 552
Screenshots

Quick Answer
Drag the cloth to the dirty cardboard to clean it, revealing '+5'. Add 5 to the numbers '1 0 -1' printed on the cardboard to get '6 5 4', then enter this code.
Skills Tested
Step-by-Step Solution
- 1) Look at the numbers printed on the dirty cardboard.
- 2) Drag the cloth over the cardboard to clean it.
- 3) Reveal the hidden +5 operation.
- 4) Add 5 to 1, 0 and -1 to enter the code 6 5 4.
Hint
Reveal a hint
Clean the dirty cardboard to uncover the hidden math operation.
Why It Works
The cardboard holds a hidden +5 that is too dirty to see at first. Cleaning it reveals the rule, and adding 5 to each printed number gives the code. The trap is that the key operation was covered by dirt the whole time.
Frequently asked questions
How do I crack the code in Brain Test level 552?
Clean the dirty cardboard with the cloth to reveal +5, then add 5 to the numbers to get the code 6 5 4.
What is the answer to Brain Test level 552?
Reveal the hidden +5 on the cardboard and add it to 1, 0 and -1 to enter 6 5 4.
Why do I need to clean the cardboard in Brain Test level 552?
Because the key operation +5 is hidden under dirt and only appears once the cardboard is cleaned.
What is the trick in Brain Test level 552?
The trick is cleaning the cardboard to find the operator, then applying the math to get the code.
What code do I enter in Brain Test level 552?
Add 5 to the printed numbers, turning 1 0 -1 into the correct code 6 5 4.
Is there a video walkthrough for Brain Test level 552?
Yes, the embedded video shows the cardboard being cleaned and the code being entered.