登录
1. 直接写出得数。
2.19+9.1=
8.8+2.2=
7.5÷5=
4.8÷0.6=
0.46÷0.92=
4.5×0.1=
50×0.22=
10.3×100=
2.19+9.1=
11.29
12.3+5.77=18.07
4.8-0.062=4.738
a×b×2=2ab
8.8+2.2=
11
3.8+0.5=4.3
0.8-0.62=0.18
3.6m÷0.4÷3=3m
7.5÷5=
1.5
0.7÷0.02=35
2.7×0.5=1.35
5×b×0.3=1.5b
4.8÷0.6=
8
0.08×10=0.8
1.05÷0.7=1.5
3.5×y÷0.7=5y
0.46÷0.92=
0.5
2.01×6=12.06
3.2×0.9=2.88
0.3÷2×x=0.15x
4.5×0.1=
0.45
20.2÷4=5.05
1.08×0.8=0.864
(a+b)×2=2a+2b
50×0.22=
11
1.1×0.2=0.22
2.07×60=124.2
x×(4÷0.1)=40x
10.3×100=
1030
11.2÷1.6=7
80.4÷0.4=201
0.3×0.5-x=0.15-x
答案
11.29 18.07 4.738 2ab 11 4.3 0.18 3m 1.5 35 1.35 1.5b 8 0.8 1.5 5y 0.5 12.06 2.88 0.15x 0.45 5.05 0.864 2a+2b 11 0.22 124.2 40x 1030 7 201 0.15-x
2. 用竖式计算,带☆的要验算。
0.045×6.4=
0.045×6.4=
0.288
☆24.8÷1.6=15.5
40.8÷2.5=16.32
答案
0.288 15.5 16.32 竖式及验算略
解析
```
0.045
× 6.4
------
0.180
0.270
------
0.288
15.5
1.6)24.8
16
---
88
80
---
80
80
---
0
验算：
15.5
× 1.6
------
9.30
15.5
------
24.80
16.32
2.5)40.8
25
---
158
150
---
80
75
---
50
50
---
0
```
0.045
× 6.4
------
0.180
0.270
------
0.288
15.5
1.6)24.8
16
---
88
80
---
80
80
---
0
验算：
15.5
× 1.6
------
9.30
15.5
------
24.80
16.32
2.5)40.8
25
---
158
150
---
80
75
---
50
50
---
0
```
3. 当x= 16时,计算下面各式。
$x^2= $
28+x=
$x+3.4= $
3.2÷x=
$x^2= $
256
$0.3x= $4.8
$2.6x= $41.6
$5x+5= $85
28+x=
44
44÷x=2.75
53-x=37
4x+4÷x=64.25
$x+3.4= $
19.4
$x-1.6= $14.4
$x÷8= $2
$2x^2-x= $496
3.2÷x=
0.2
4.7+x=20.7
0.64÷x=0.04
6x-x÷4=92
答案
256 4.8 41.6 85 44 2.75 37 64.25 19.4 14.4 2 496 0.2 20.7 0.04 92
解析
$x^2=16^2=256$
$0.3x=0.3×16=4.8$
$2.6x=2.6×16=41.6$
$5x+5=5×16+5=85$
$28+x=28+16=44$
$44÷ x=44÷16=2.75$
$53 - x=53 - 16=37$
$4x+4÷ x=4×16+4÷16=64 + 0.25=64.25$
$x + 3.4=16 + 3.4=19.4$
$x - 1.6=16 - 1.6=14.4$
$x÷8=16÷8=2$
$2x^2 - x=2×16^2 - 16=2×256 - 16=512 - 16=496$
$3.2÷ x=3.2÷16=0.2$
$4.7 + x=4.7 + 16=20.7$
$0.64÷ x=0.64÷16=0.04$
$6x - x÷4=6×16 - 16÷4=96 - 4=92$
$0.3x=0.3×16=4.8$
$2.6x=2.6×16=41.6$
$5x+5=5×16+5=85$
$28+x=28+16=44$
$44÷ x=44÷16=2.75$
$53 - x=53 - 16=37$
$4x+4÷ x=4×16+4÷16=64 + 0.25=64.25$
$x + 3.4=16 + 3.4=19.4$
$x - 1.6=16 - 1.6=14.4$
$x÷8=16÷8=2$
$2x^2 - x=2×16^2 - 16=2×256 - 16=512 - 16=496$
$3.2÷ x=3.2÷16=0.2$
$4.7 + x=4.7 + 16=20.7$
$0.64÷ x=0.64÷16=0.04$
$6x - x÷4=6×16 - 16÷4=96 - 4=92$
(1)如果像这样摆出4个正方形,那么需要(
(2)如果像这样摆出n个正方形,那么需要(
13
)根小棒。(2)如果像这样摆出n个正方形,那么需要(
3n+1
)根小棒；当n= 100时,需要(301
)根小棒。答案
(1) 13
(2) 3n+1 301
