13又八分之七减（8.16减1.875）减0.84简便方法
=13 + 7/8 - 8.16 + 1+ 7/8 - 0.84
=13 + 1 - (8.16+ 0.84)+ 7/8+ 7/8
= 14 - 9 + 14/8
= 5 + 7/4
= 6 又4分之3