| 24+16×11÷8 | 1.25×32×2.5 | (2.8+3.85÷3.5)×0.2 |
![]() | 10.9-( +9.6÷4) | . |
=24+176÷8,
=24+22,
=46;
(2)1.25×32×2.5,
=1.25×4×8×2.5,
=(1.25×8)×(2.5×4),
=10×10,
=100;
(3)(2.8+3.85÷3.5)×0.2,
=(2.8+1.1)×0.2,
=3.9×0.2,
=0.78;
(4)
+
-
+
,=(
-
)+(
+
),=
+1,=1
;(5)10.9-(
+9.6÷4),=10.9-(
+2.4),=10.9-2.8,
=8.1;
(6)
,=
÷[1-
],=
÷
,=5.
分析:(1)先算乘法,再算除法,最后算加法;
(2)先把32分解成4×8,再运用乘法结合律简算;
(3)先算小括号里面的除法,再算小括号里面的加法,最后算括号外的乘法;
(4)根据加法结合律简算;
(5)先算小括号里面的除法,再算小括号里面的加法,最后算括号外的减法;
(6)先算小括号里面的加法,再算中括号里面的减法,最后算括号外的除法.
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
