Question

五年级简便计算

7.5*3.1/25*100
36.5*6.2+28*0.365+3.65
999.9*599.9+199.99

Answer 1

1、 7.5*3.1/2.5*100
=7.5/2.5*3.1*100
=3*3100
=9300
2、36.5*6.2+28*0.365+3.65
=36.5*6.2+2.8*3.65+3.65
=3.65*（6.2+2.8+1）
=3.65*1.
=36.5
3、999.9*599.9+199.9
=1000×599+0.1×599.9+200-0.1
=5990+59.9+200-0.1
=6049.9+200-0.1
=6249.9-0.1
=6249.8

999.9*599.9+199.9
=(1000-0.1)*599.9+(200-0.1)
=1000*599.9-0.1*599.9+200-0.1
=599900-599.99+200-0.1
=599900-(600-0.1)+200-0.1
=599900-600+0.1+200-0.1
=599900-600+200
=599500

999.9X599.9+199.9
=(1000-0.1)X599.9+(200-0.1)
=1000X599.9-0.1X599.9+200-0.1
=599900-59.99+200-0.1
=599900-(60-0.01)+200-0.1
=599900-60+0.01+200-0.1
=599900+200+0.01-60-0.1
=600039.91

999.9×599.9+199.9
= （1000－0．1）×599.9+199.9
＝1000×599.9－0.1×599.9+199.9
＝599900－59.9+199.9
＝599900＋140
＝60040

自己看一下哪个对吧，看我那么辛苦，给分吧~~~~~~~~

Answer 2

下面是简便运算：
2.34×11-117×0.22
=（2.34×50）×（11÷50）-117×0.22
=117×0.22-117×0.22
=0
19.99×19.98-19.97×19.96
=19.99×（19.97+0.01）-19.97×19.96
=19.97×0.03+0.1999
=0.799
199.199×198-1孩亥粉酵莠寂疯檄弗漏98.198×199
=199.199×198-198.198×（198+1）
=199.199-198.198×198-198.198
=198.198-198.198
=0
18.9×178.178+0.49-17.8×17.8×189.189
=（17.8+1.1）×178.178+0.49-17.8×17.8×189.189
=17.8×（178.178-17.8×189.189）+1.1×178.178+0.49
=-56771.07436+195.9958+0.49
=-56574.58856

Answer 3

2.34*11-117*0.22
=（2.34-2.34）*11
=0
19.99*19.98-19.97*19.96
=19.99*（19.97+0.01）-19.97*19.96
=19.97*0.03+0.1999
=0.799
199.199*198-198.198*199
=199.199*198-198.198*（198+1）
=199.199-198.198*198-198.198
=198.198-198.198
=0
18.9*178.178+0.49-17.8*17.8*189.189
=（17.8+1.1）*178.178+0.49-17.8*17.8*189.189
=17.8*（178.178-17.8*189.189）+1.1*178.178+0.49
=-56771.07436+195.9958+0.49
=-56574.58856
五年级的小朋友应该用不着负数吧
老师有没有搞错啊

Answer 4

您好！
7.36乘3.4+6.6乘7.36
=7.36×（3.4+6.6）
=7.36×10
=73.6
5.8乘9.9+5.8乘0.1
=5.8×（9.9+0.1）
=5.8×10
=58
1.25乘2.5乘32
=（1.25×8）×（2.5×4）
=10×10
=100
48乘0.25
=（4×0.25）×12
=12
8.3乘9.9
=8.3×（10-0.1）
=8.3×10-8.3×0.1
=83-0.83
=82.17
100.1乘3.4
=（100+0.1）×3.4
=100×3.4+0.1×3.4
=340+0.34
=340.34

Answer 5

(
3又7/11
+
1又12/13
)
÷
(
1又5/11
+
10/13
)
=(40/11+25/13)÷(16/11+10/13)
=[(40x13+25x11)÷(11x13)]÷[(16x13+11x10)÷(11x13)]
=(40x13+25x11)÷(16x13+11x10)
=(520+275)÷(208+110)
=795÷318