四个9加起来为什么等于100?

页面:/news/view-1156081/ | 耗时:0.8022 s | 内存:1.89 MB | 查询:4 | 缓存读取:4 写入:0 | 加载文件:23
select * from tbl_Articles WHERE ArticleID=1156081 LIMIT 0,1
select * from tbl_Articles_data WHERE ArticleID=1156081 LIMIT 0,1
select * from tbl_Articles_sphinx where id=1156081 LIMIT 0,1
SELECT ArticleID,Title FROM tbl_Articles WHERE ArticleID IN(2516732,2932825,3490682,902937,3254380,3192681,1156081,589428,3302751,1191974,559941,2250822,1050086,442594,646516,775641,1091692,3100591,1151673,2261761,1484888,540933,3104525,3264581,1214247,3476372,2138606,591831,406765,1891232) ORDER BY field (ArticleID,2516732,2932825,3490682,902937,3254380,3192681,1156081,589428,3302751,1191974,559941,2250822,1050086,442594,646516,775641,1091692,3100591,1151673,2261761,1484888,540933,3104525,3264581,1214247,3476372,2138606,591831,406765,1891232)