When calculating the addition, I read the question wrong. Eight in the unit is regarded as 3, and six in the percentile is regarded as 9. The wrong sums are 18 and 2 1. What should be the correct number? The wrong sum should be 18+38+0.

8 is regarded as 3 in the unit, and 5 is omitted, so 5 should be added to the result;

6 is regarded as 9 in the percentile, 0.03 is too much, and the result is to subtract 0.03. The final result is the correct number:

18.2 1+5-0.03=23. 18