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1. 把$\frac{2}{3}$m长的绳子平均分成4段,每段占全长的(
$\frac{1}{4}$
),每段长($\frac{1}{6}$
)m。答案
$\frac{1}{4}$ $\frac{1}{6}$
2. 甲、乙两地相距10 km,小刚骑车用$\frac{5}{6}$小时行完全程。他平均每小时行(
12
)km,他平均每行1 km用($\frac{1}{12}$
)小时。答案
12 $\frac{1}{12}$
3. 5 g盐放入20 g水中,盐占盐水的(
$\frac{1}{5}$
)。答案
$\frac{1}{5}$
解析
盐水质量：$5 + 20 = 25\ g$
盐占盐水的比例：$\frac{5}{25} = \frac{1}{5}$
$\frac{1}{5}$
盐占盐水的比例：$\frac{5}{25} = \frac{1}{5}$
$\frac{1}{5}$
4. 在$◯$里填上“$＞$”“$＜$”或“$=$”。
$\frac{9}{10}÷\frac{1}{3}◯$
$\frac{9}{10}÷\frac{1}{3}◯$
=
$\frac{9}{10}×3$ $\frac{15}{16}÷\frac{1}{5}◯$＞
$\frac{15}{16}×\frac{1}{5}$ $\frac{2}{3}×\frac{1}{4}×\frac{3}{5}◯$＜
$\frac{2}{3}÷\frac{1}{4}÷\frac{3}{5}$答案
= ＞ ＜
1. $\frac{1}{8}$m的$\frac{2}{3}和几米的\frac{1}{6}$一样长？列式为(
A.$\frac{1}{8}×\frac{2}{3}×\frac{1}{6}$
B.$\frac{1}{8}×\frac{2}{3}÷\frac{1}{6}$
C.$\frac{1}{8}÷\frac{2}{3}×\frac{1}{6}$
D.$\frac{1}{8}÷\frac{2}{3}÷\frac{1}{6}$
B
)。A.$\frac{1}{8}×\frac{2}{3}×\frac{1}{6}$
B.$\frac{1}{8}×\frac{2}{3}÷\frac{1}{6}$
C.$\frac{1}{8}÷\frac{2}{3}×\frac{1}{6}$
D.$\frac{1}{8}÷\frac{2}{3}÷\frac{1}{6}$
答案
B
解析
$\frac{1}{8} × \frac{2}{3} ÷ \frac{1}{6}$，B
2. $\frac{4}{15}÷\frac{7}{9}×\frac{9}{7}◯\frac{4}{15}÷(\frac{7}{9}×\frac{9}{7})$中,$◯$里应填(
A.$＞$
B.$＜$
C.$=$
A
)。A.$＞$
B.$＜$
C.$=$
答案
A
解析
左边：$\frac{4}{15}÷\frac{7}{9}×\frac{9}{7}=\frac{4}{15}×\frac{9}{7}×\frac{9}{7}=\frac{4}{15}×\frac{81}{49}=\frac{324}{735}$
右边：$\frac{4}{15}÷(\frac{7}{9}×\frac{9}{7})=\frac{4}{15}÷1=\frac{4}{15}=\frac{196}{735}$
$\frac{324}{735}＞\frac{196}{735}$，故$◯$里应填$＞$。
A
右边：$\frac{4}{15}÷(\frac{7}{9}×\frac{9}{7})=\frac{4}{15}÷1=\frac{4}{15}=\frac{196}{735}$
$\frac{324}{735}＞\frac{196}{735}$，故$◯$里应填$＞$。
A
3. 一辆汽车$\frac{1}{3}$小时行驶30 km,照这样的速度,$\frac{3}{5}$小时能行驶(
A.54
B.90
C.150
D.120
A
)km。A.54
B.90
C.150
D.120
答案
A
解析
汽车速度为 $30÷\frac{1}{3}=90$ km/h，$\frac{3}{5}$小时行驶路程为 $90×\frac{3}{5}=54$ km。A
三、我会算。
$\frac{2}{11}÷\frac{1}{9}÷\frac{19}{22}$ $\frac{9}{5}×\frac{2}{3}÷\frac{18}{35}$ $(\frac{3}{4}-\frac{1}{12})÷\frac{1}{6}$
$\frac{3}{4}×\frac{5}{6}÷\frac{15}{16}$ $\frac{3}{5}÷(\frac{3}{10}+\frac{5}{8})$ $(\frac{7}{8}-\frac{5}{6})÷\frac{11}{24}$
$\frac{2}{11}÷\frac{1}{9}÷\frac{19}{22}$ $\frac{9}{5}×\frac{2}{3}÷\frac{18}{35}$ $(\frac{3}{4}-\frac{1}{12})÷\frac{1}{6}$
$\frac{3}{4}×\frac{5}{6}÷\frac{15}{16}$ $\frac{3}{5}÷(\frac{3}{10}+\frac{5}{8})$ $(\frac{7}{8}-\frac{5}{6})÷\frac{11}{24}$
答案
$\frac{36}{19}$ $\frac{7}{3}$ 4 $\frac{2}{3}$ $\frac{24}{37}$ $\frac{1}{11}$
解析
$\frac{2}{11}÷\frac{1}{9}÷\frac{19}{22}=\frac{2}{11}×9×\frac{22}{19}=\frac{2×9×2}{19}=\frac{36}{19}$
$\frac{9}{5}×\frac{2}{3}÷\frac{18}{35}=\frac{9}{5}×\frac{2}{3}×\frac{35}{18}=\frac{1×2×7}{5×1×2}=\frac{7}{3}$
$(\frac{3}{4}-\frac{1}{12})÷\frac{1}{6}=(\frac{9}{12}-\frac{1}{12})×6=\frac{8}{12}×6=4$
$\frac{3}{4}×\frac{5}{6}÷\frac{15}{16}=\frac{3}{4}×\frac{5}{6}×\frac{16}{15}=\frac{1×1×4}{1×3×1}=\frac{4}{3}$
$\frac{3}{5}÷(\frac{3}{10}+\frac{5}{8})=\frac{3}{5}÷(\frac{12}{40}+\frac{25}{40})=\frac{3}{5}÷\frac{37}{40}=\frac{3}{5}×\frac{40}{37}=\frac{24}{37}$
$(\frac{7}{8}-\frac{5}{6})÷\frac{11}{24}=(\frac{21}{24}-\frac{20}{24})×\frac{24}{11}=\frac{1}{24}×\frac{24}{11}=\frac{1}{11}$
$\frac{9}{5}×\frac{2}{3}÷\frac{18}{35}=\frac{9}{5}×\frac{2}{3}×\frac{35}{18}=\frac{1×2×7}{5×1×2}=\frac{7}{3}$
$(\frac{3}{4}-\frac{1}{12})÷\frac{1}{6}=(\frac{9}{12}-\frac{1}{12})×6=\frac{8}{12}×6=4$
$\frac{3}{4}×\frac{5}{6}÷\frac{15}{16}=\frac{3}{4}×\frac{5}{6}×\frac{16}{15}=\frac{1×1×4}{1×3×1}=\frac{4}{3}$
$\frac{3}{5}÷(\frac{3}{10}+\frac{5}{8})=\frac{3}{5}÷(\frac{12}{40}+\frac{25}{40})=\frac{3}{5}÷\frac{37}{40}=\frac{3}{5}×\frac{40}{37}=\frac{24}{37}$
$(\frac{7}{8}-\frac{5}{6})÷\frac{11}{24}=(\frac{21}{24}-\frac{20}{24})×\frac{24}{11}=\frac{1}{24}×\frac{24}{11}=\frac{1}{11}$
