脑洞大师 4 第 309 关：How is this correct?
脑洞大师 4 第 309 关
通关截图
快速答案
Use the eraser on the number 5 to reveal '5-5', making the equation correct.
考察能力
分步解法
- 1) Read the equation and notice which number makes it look wrong.
- 2) Take the eraser and rub it across that number.
- 3) Watch the digit break apart into a subtraction sign.
- 4) Confirm the equation now balances correctly.
提示
查看提示
Erase the written number to turn it into a minus sign.
为什么有效
This trick turns a digit into part of the operation itself. By changing 5 into a 5 minus something, the equation becomes mathematically valid, rewarding close observation over normal arithmetic.
常见问题
How do I solve Brain Test 4 Level 309?
Use the eraser on the number 5 so it reveals a minus sign, which makes the equation correct.
What is the answer to Brain Test 4 Level 309?
Erase part of the number so it becomes a subtraction sign, turning the statement into a valid equation.
What is the trick in Brain Test 4 Level 309?
The trick is that a written number can be erased into a minus sign, which fixes the math without doing any calculation.
Why do I need to use the eraser in Brain Test 4 Level 309?
Because wiping across the digit changes it into a minus sign, and that transformation is what finally makes the equation work.
Is there a video walkthrough for Brain Test 4 Level 309?
Yes, the embedded video on this page shows the eraser being used on the number to turn it into the needed symbol.
How do I avoid getting stuck in Brain Test 4 Level 309?
Do not try to solve it with numbers alone; pick up the eraser and swipe across the digit to reveal the missing minus sign.