0.1+0.2+0.3.+、、、、0.87+0.88+0.

0.0.8都×10,变成1~8
因为0.10=0.1,所以0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8也都×10,变成1,2,3,4,5,6,7,8
（1+2+3+4+5+6+7+8）×2=36
除上面所说的数外,其他数×10
所以11+12...+19+21...+29+31...+39+41+...以此类推,最后等于3600
3600÷100+36÷10=39.6
最终答案39.6