The sum on the side is incorrect. To correct it, it is enough to replace a certain digit in all the places where it appears in the equation with another digit. Which is the incorrect digit and what is its correct substitute?
At first inspection, we can admit that the three digits to the right of the numbers are correct, that is, the digits $0,1,3,4,5$, 6 and 8 are correct. Therefore, among the digits 2, 7, and 9, one of them is wrong. The digit 9 is correct, because if we change it, the sum with 2 will not be correct. Thus, only 2 and 7 remain. If the 7 were wrong, then the 2 would be correct, but this is not possible, because $1+4+2=7$. Therefore, it is the 2 that is wrong and must be replaced. Looking again at the sum $1+4+2$, we see that the result is a number with the unit digit equal to 1. Therefore, the digit 2 must be replaced four times by 6. By making this replacement, we verify that the sum is correct.