2. 直接写得数。(a不为0)(4分)
$0.2^{3}+3^{2}=$ $\frac{1}{4}-\frac{1}{7}=$ $0.125×0.25=$ $2.4a×5a=$
$4.7+3=$ $\frac{1}{3}a÷\frac{1}{6}a=$ $\frac{5}{6}+\frac{1}{6}÷\frac{1}{6}=$ $\frac{3}{4}×\frac{3}{5}÷\frac{3}{4}×\frac{3}{5}=$
$0.2^{3}+3^{2}=$ $\frac{1}{4}-\frac{1}{7}=$ $0.125×0.25=$ $2.4a×5a=$
$4.7+3=$ $\frac{1}{3}a÷\frac{1}{6}a=$ $\frac{5}{6}+\frac{1}{6}÷\frac{1}{6}=$ $\frac{3}{4}×\frac{3}{5}÷\frac{3}{4}×\frac{3}{5}=$
答案：2.9.008 $\frac{3}{28}$ $\frac{1}{32}$ 12a² 7.7 2 1$\frac{5}{6}$ $\frac{9}{25}$
3. 计算下面各题，能简算的要简算。(6分)
$(13×\frac{7}{12}-\frac{7}{12})÷\frac{14}{25}$ $24×(\frac{5}{12}+\frac{7}{25})×25$ $\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}$
$(13×\frac{7}{12}-\frac{7}{12})÷\frac{14}{25}$ $24×(\frac{5}{12}+\frac{7}{25})×25$ $\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}$
答案：3.(13×$\frac{7}{12}$ - $\frac{7}{12}$)÷$\frac{14}{25}$
=(13×$\frac{7}{12}$ - $\frac{7}{12}$)×$\frac{25}{14}$
=$\frac{7}{12}$×(13 - 1)×$\frac{25}{14}$
=$\frac{7}{12}$×12×$\frac{25}{14}$
=$\frac{25}{2}$
24×($\frac{5}{12}$ + $\frac{7}{25}$)×25
=24×$\frac{5}{12}$×25 + 24×$\frac{7}{25}$×25
=250 + 168
=418
$\frac{1}{4}$ + $\frac{1}{8}$ + $\frac{1}{16}$ + $\frac{1}{32}$ + $\frac{1}{64}$
=$\frac{16}{64}$ + $\frac{8}{64}$ + $\frac{4}{64}$ + $\frac{2}{64}$ + $\frac{1}{64}$
=$\frac{31}{64}$
=(13×$\frac{7}{12}$ - $\frac{7}{12}$)×$\frac{25}{14}$
=$\frac{7}{12}$×(13 - 1)×$\frac{25}{14}$
=$\frac{7}{12}$×12×$\frac{25}{14}$
=$\frac{25}{2}$
24×($\frac{5}{12}$ + $\frac{7}{25}$)×25
=24×$\frac{5}{12}$×25 + 24×$\frac{7}{25}$×25
=250 + 168
=418
$\frac{1}{4}$ + $\frac{1}{8}$ + $\frac{1}{16}$ + $\frac{1}{32}$ + $\frac{1}{64}$
=$\frac{16}{64}$ + $\frac{8}{64}$ + $\frac{4}{64}$ + $\frac{2}{64}$ + $\frac{1}{64}$
=$\frac{31}{64}$
4. 解方程或比例。(6分)
$x-\frac{3}{4}x=\frac{7}{10}$ $\frac{x}{5}=40\%:\frac{1}{3}$ $\frac{7}{5}-20\%x=0.4$
$x-\frac{3}{4}x=\frac{7}{10}$ $\frac{x}{5}=40\%:\frac{1}{3}$ $\frac{7}{5}-20\%x=0.4$
答案：4.x - $\frac{3}{4}$x = $\frac{7}{10}$ $\frac{x}{5}$ = 40%:$\frac{1}{3}$
解:$\frac{1}{4}$x = $\frac{7}{10}$ 解:$\frac{x}{5}$ = $\frac{2}{5}$:$\frac{1}{3}$
x = $\frac{14}{5}$ $\frac{1}{3}$x = $\frac{2}{5}$×5
$\frac{1}{3}$x = 2
x = 6
$\frac{7}{5}$ - 20%x = 0.4
解:0.2x = $\frac{7}{5}$ - 0.4
0.2x = 1
x = 5
解:$\frac{1}{4}$x = $\frac{7}{10}$ 解:$\frac{x}{5}$ = $\frac{2}{5}$:$\frac{1}{3}$
x = $\frac{14}{5}$ $\frac{1}{3}$x = $\frac{2}{5}$×5
$\frac{1}{3}$x = 2
x = 6
$\frac{7}{5}$ - 20%x = 0.4
解:0.2x = $\frac{7}{5}$ - 0.4
0.2x = 1
x = 5
1. 第一小组的同学正进行一分钟跳绳测试，老师以100下作为标准，超过的用正数表示，不足的用负数表示。这组同学的成绩(单位：下)为+13，+5，-4，+1，+9，-2，-7，+12，+9，-26。这组同学的平均成绩是多少下？(4分)
答案：1.100 + $\frac{1}{10}$×(13 + 5 - 4 + 1 + 9 - 2 - 7 + 12 + 9 - 26)=101(下)
解析：
100 + $\frac{1}{10}×(13 + 5 - 4 + 1 + 9 - 2 - 7 + 12 + 9 - 26)$
= 100 + $\frac{1}{10}×10$
= 100 + 1
= 101(下)
答：这组同学的平均成绩是101下。
= 100 + $\frac{1}{10}×10$
= 100 + 1
= 101(下)
答：这组同学的平均成绩是101下。
2. 劳技课上，小泽用162厘米长的铁丝焊了一个长、宽、高的比是$5:3:2$的长方体框架(损耗2厘米)，放置这个长方体框架至少需要多大的空间？(4分)
答案：2.(162 - 2)÷4÷(5 + 3 + 2)=4(厘米)
4×5 = 20(厘米) 4×3 = 12(厘米)
4×2 = 8(厘米) 20×12×8 = 1920(立方厘米)
4×5 = 20(厘米) 4×3 = 12(厘米)
4×2 = 8(厘米) 20×12×8 = 1920(立方厘米)