题目内容
7.计算题$\frac{x}{0.3}$=$\frac{7.5}{0.25}$ | $\frac{14}{15}$+($\frac{3}{4}$-$\frac{2}{3}$)÷$\frac{1}{5}$ | 1080×(15.7-30.9÷3) |
(2$\frac{1}{6}$-0.5)÷[(1.2+1.55)×$\frac{20}{33}$] | [3.86-(0.2+$\frac{1}{3}$×4$\frac{1}{2}$)]÷13.5 | (2512+5066÷17)×554 |
分析 (1)根据比例的基本性质进行解答;
(2)先算减法,再算除法,最后算加法;
(3)先算除法,再算减法,最后算乘法;
(4)先算减法和加法,再算乘法,最后算除法;
(5)先算除法,再算加法,再算减法,最后算除法;
(6)先算除法,再算加法,最后算乘法.
解答 解:(1)$\frac{x}{0.3}$=$\frac{7.5}{0.25}$
0.25x=0.3×7.5
0.25x÷0.25=0.3×7.5÷0.25
x=9;
(2)$\frac{14}{15}$+($\frac{3}{4}$-$\frac{2}{3}$)÷$\frac{1}{5}$
=$\frac{14}{15}$+$\frac{1}{12}$÷$\frac{1}{5}$
=$\frac{14}{15}$+$\frac{5}{12}$
=$\frac{81}{60}$;
(3)1080×(15.7-30.9÷3)
=1080×(15.7-10.3)
=1080×5.4
=5832;
(4)(2$\frac{1}{6}$-0.5)÷[(1.2+1.55)×$\frac{20}{33}$]
=$\frac{5}{3}$÷[2.75×$\frac{20}{33}$]
=$\frac{5}{3}$÷$\frac{5}{3}$
=1;
(5)[3.86-(0.2+$\frac{1}{3}$×4$\frac{1}{2}$)]÷13.5
=[3.86-(0.2+$\frac{3}{2}$)]÷13.5
=[3.86-1.7]÷13.5
=2.16÷13.5
=0.16;
(6)(2512+5066÷17)×554
=(2512+298)×554
=2810×554
=1556740.
点评 解比例是利用比例的基本性质,即比例的两个内项的积等于两个外项的积.
考查了分数、小数和再算四则混合运算,注意运算顺序和运算法则,然后再进一步计算.
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
3.86+1.4= | 0.365÷1000×100= | 10-0.99= |
25×4÷25×2= | 83+20-83+20= | 0.65-0.56= |
2.16+3.84= |