1. 直接写出得数。(8分)
$\frac{5}{16}×\frac{8}{15}=$
$5.6+0.4=$
$245-155=$
$3+\frac{3}{7}÷3=$
$1÷0.01=$
$5.1×0.4=$
$0.125×\frac{1}{5}=$
$1-\frac{5}{6}+\frac{1}{6}=$
$0.29+0.1=$
$1.05÷0.5=$
$4.1×0.02=$
$\frac{1}{4}÷\frac{1}{5}÷\frac{1}{6}×\frac{1}{5}=$
$6.8÷0.04=$
$0.3×320=$
$7.2÷\frac{1}{2}=$
$4.5÷15×0=$
答案:1. $\frac{1}{6}$ 6 90 $3\frac{1}{7}$ 100 2.04 0.025 $\frac{1}{3}$ 0.39 2.1 0.082 $\frac{3}{2}$ 170 96 14.4 0
2. 用竖式计算,带*的要验算。(7分)
4.64×0.25=
15. 6÷0.15=
9.35×6.5≈
(精确到百分位)
答案:2. 1.16 104 60.78 竖式及验算略
3. 计算下面各题,能简算的要简算。(12 分)
$0.8×\frac{3}{5}×12.5$
$\frac{17}{25}+(\frac{7}{8}+\frac{1}{25})×8$
$\frac{3}{8}×[\frac{8}{9}÷(\frac{5}{6}-\frac{3}{4})]$
$72.4 - 4.46 - 5.54$
$(7.2 + 3.6)÷\frac{9}{13}$
$0.72÷[(2.7 + 3.3)×0.08]$
答案:3. 6 8 4 62.4 15.6 1.5
1. 已知$17×23=391$,根据这道乘法算式的结果,可以直接得出$0.17×230=(\quad)$;$\frac{17}{5}×\frac{23}{3}$的积的计数单位是$(\quad)$,结果是$(\quad)$
答案:1. 39.1 $\frac{1}{15}$ $\frac{391}{15}$