1、在列括号里填上适当的数
(1)8-(-5)+(-4)-3=8+(5)+(-4)+(-3)
(2)(-1/2)+(-1/3)-(-1/4)-(-1/5)=
(- 1/2)+(-1/3)+(1/4)+(1/5)
2、计算
(1)(+6)-(-3)+(-2)-(+6)
=6+3-2-6
=1
(2)(+4.2)-(-5.8)-3
=4.2+5.8-3
=10-3
=7
(3)9-(-0.3)+(-6)-(-4.7)
=9+0.3-6+4.7
=15-6
=9
(4)(+1/3)-(+5/6)+(-1/6)-(-2/3)
=1/3-5/6-1/6+2/3
=1-2/3
=1/3
3、计算
(1)-4.2+5.7-8.4+10
=-4.2-8.4+5.7+10
=-12.6+5.7+10
=-6.9+10
=3.1
(2)6.1-3.7-4.9+1.8
=6.1-(3.7+4.9-1.8)
=6.1-6.8
=-0.3
(3)1/3-2/3+1
=-1/3+1
=2/3
(4)-1/4+5/6+2/3-1/2
=-1/4-2/4+6/5+6/4
=-0.75+1.5
=3/4(0.75)
4、-3,+5与-7的和比它们的绝对值的和小多少?
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