| 17255÷85×49-749 | 〔 -(0.2+ )×4.5〕÷(7.05+ ) | 2.75+ +10.2+![]() |
9.9+2.5× -2.7÷![]() | ÷〔0.5÷ - ×(0.4+ )〕 |
解:(1)17255÷85×49-749, =203×49-749, =9947-749, =9198; (2)〔 -(0.2+ )×4.5〕÷(7.05+ ),=【 - ×4.5】÷13.5,=【3.75-2.4】÷13.5, =1.35÷13.5, =0.1; | ||
(3)2.75+ +10.2+ ,=(2.75+1.25)+(3.8+10.2), =4+14, =18; (4)9.9+2.5× -2.7÷ ,=9.9+2-1.2, =10.7; (5) ÷〔0.5÷ - ×(0.4+ )〕,= ÷( - × ),= ÷ ,=22. |
分析:(1)先算除法,再算乘法,最后算减法;
(2)先算括号里面的,再算括号外面的除法;
(3)运用加法交换、结合律简算;
(4)乘除法同时脱式,再算加法,最后算减法;
(5)先算括号里面的,再算括号外面的除法.
点评:此题属于分数四则混合运算,要按照运算顺序计算,能简算的要简算.
-(0.2+
)×4.5〕÷(7.05+
)
+10.2+
-2.7÷
÷〔0.5÷
-
×(0.4+
)〕
×4.5】÷13.5,
),
,