This Mental Math Challenge Seems Simple… But It Traps Almost Everyone!

The Right Method to Avoid Errors

The solution is surprisingly simple: break it down. Go through the calculation step by step, without skipping, as if explaining to someone else.

For example:
1000 + 40 = 1040
1040 + 1000 = 2040
2040 + 30 = 2070
2070 + 1000 = 3070
3070 + 20 = 3090
3090 + 1000 = 4090
4090 + 10 = 4100

The correct answer is 4100, not 5000.