脱式计算,能简算的要简算
|
(1)
×4×2 5
,3 4
=
×(4×2 5
),3 4
=
×3,2 5
=
;6 5
(2)
×7+3 8
,3 8
=
×(7+1),3 8
=
×8,3 8
=3;
(3)55×
-32×6 11
,1 4
=30-8,
=22;
(4)0.125×32×2.5,
=0.125×(4×8)×2.5,
=(0.125×8)×(4×2.5),
=1×10,
=10;
(5)99.9+0.12+0.1+0.88,
=(99.9+0.1)+(0.12+0.88),
=100+1,
=101;
(6)9+99+999+9×
,1 3
=9+99+999+3,
=9+99+999+(1+1+1),
=(9+1)+(99+1)+(999+1),
=10+100+1000,
=1110.