(-2)-(+2/3)
=-2-2/3
=-2又2/3
(-16又3/4)-(-10又1/4)-(+1又1/2)
=-16又3/4+10又1/4-1又1/2
=-6又1/2-1又1/2
=-8
-4.2+5.7-8.4+10
=1.5-8.4+10
=-6.9+10
=3.1
-1/4+5/6+2/3-1/2
=-3/12+10/12+8/12-6/12
=7/12+8/12-6/12
=15/12-6/12
=9/12
=3/4
12-（-18）+（-7）-15
=12+18-7-15
=-8
4.7-（-8.9）-7.5+（-6）
=4.7+8.9-7.5-6
=13.6-7.5-6
=0.1
（-4又7/8）-（-5又1/2）+（-4又1/4）-（+3又1/8）
=-4又7/8+5又1/2-4又1/4-3又1/8
=-8+1又1/2
=-6又1/2
（-2/3）+|0-5又1/6|+|-4又5/6|+（-9又1/3）
=-2/3+（5又1/6+4又5/6）-9又1/3
=-2/3+10-9又1/3
=9又1/3-9又1/3
=0