| 0.6+32×0.25-6 | ÷[( + )× ] | 1.05×(3.8-0.8)÷6.3 | + ×99+ . |
(1)0.6+32×0.25-6,
=0.6+8-6,
=8.6-6,
=2.6;
(2)
÷[(
+
)×
],=
÷[
×
],=
÷
,=5;
(3)1.05×(3.8-0.8)÷6.3,
=1.05×3÷6.3,
=3.15÷6.3,
=0.5;
(4)
+
×99+
,=(
+
)+
×99,=
+
×99,=
×(99+1),=
×100,=
.分析:(1)先算乘法,再算加法,最后算减法;
(2)先算加法,再算乘法,最后算除法;
(3)先算减法,再算乘法,最后算除法;
(4)根据加法交换律和乘法分配律进行计算.
点评:四则运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.