用简便方法计算.这是初一的题.三克油.(1)(-2)+3+6+(-3)+2+(-4)(2)(-0.5)+3又4分之1+2.75+(-7又2分之1)

问题描述:

用简便方法计算.这是初一的题.三克油.
(1)(-2)+3+6+(-3)+2+(-4)
(2)(-0.5)+3又4分之1+2.75+(-7又2分之1)

(1)(-2)+3+6+(-3)+2+(-4)
= (-2)+2+3+(-3)+6+(-4)
=0+0+6-4
=2
(2)(-0.5)+3又4分之1+2.75+(-7又2分之1)
= (-二分之一)+(-7又2分之1)+3又4分之1+2又4分之3
= -8 +6
= -2