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(1)$1\dfrac{1}{9}$的分数单位是(
$\frac{1}{9}$
)，它有(10
)个这样的单位，再增加(8
)个这样的分数单位就是最小的质数。答案
1.(1) $\frac{1}{9}$ 10 8
(2)分母是12的最简真分数有(
4
)个，它们的和是(2
)。答案
1.(2)4 2
2. 计算。
$\dfrac{2}{15}+\dfrac{4}{15}+\dfrac{7}{15}$
$1-\dfrac{3}{25}-\dfrac{7}{25}$
$\dfrac{2}{15}+\dfrac{4}{15}+\dfrac{7}{15}$
$1-\dfrac{3}{25}-\dfrac{7}{25}$
答案
2. $\frac{13}{15}$ $\frac{3}{5}$
3. 解下列方程。
$x+\dfrac{2}{9}=\dfrac{7}{9}$
$x-\dfrac{1}{6}=\dfrac{5}{6}$
$\dfrac{2}{11}+x=\dfrac{8}{11}$
$\dfrac{17}{21}-x=\dfrac{10}{21}$
$x+\dfrac{2}{9}=\dfrac{7}{9}$
$x-\dfrac{1}{6}=\dfrac{5}{6}$
$\dfrac{2}{11}+x=\dfrac{8}{11}$
$\dfrac{17}{21}-x=\dfrac{10}{21}$
答案
3. $x=\frac{5}{9}$ $x=1$ $x=\frac{6}{11}$ $x=\frac{1}{3}$
4. 在$◯$里填上“$＞$”“$＜$”或“$=$”。
$\dfrac{9}{10}-\dfrac{3}{10}◯\dfrac{4}{5}-\dfrac{1}{5}$
$\dfrac{19}{12}-\dfrac{5}{12}-\dfrac{1}{12}◯\dfrac{7}{10}+\dfrac{1}{10}+\dfrac{3}{10}$
$\dfrac{14}{17}-\dfrac{2}{17}-\dfrac{3}{17}◯\dfrac{2}{19}+\dfrac{2}{19}+\dfrac{5}{19}$
$\dfrac{1}{6}+\dfrac{1}{6}+\dfrac{5}{6}◯2-\dfrac{1}{6}$
$\dfrac{9}{10}-\dfrac{3}{10}◯\dfrac{4}{5}-\dfrac{1}{5}$
$\dfrac{19}{12}-\dfrac{5}{12}-\dfrac{1}{12}◯\dfrac{7}{10}+\dfrac{1}{10}+\dfrac{3}{10}$
$\dfrac{14}{17}-\dfrac{2}{17}-\dfrac{3}{17}◯\dfrac{2}{19}+\dfrac{2}{19}+\dfrac{5}{19}$
$\dfrac{1}{6}+\dfrac{1}{6}+\dfrac{5}{6}◯2-\dfrac{1}{6}$
答案
4. = ＜ ＞ ＜
5. 有三根电线，第一根电线比第二根短$\dfrac{5}{9}$分米，第三根电线比第二根长$\dfrac{1}{9}$分米。第三根电线比第一根长多少分米？
答案
5. $\frac{5}{9}+\frac{1}{9}=\frac{2}{3}$(分米)
6. 计算。
$\dfrac{1}{2025}+\dfrac{2}{2025}+\dfrac{3}{2025}+\dots+\dfrac{2024}{2025}$
$\dfrac{1}{2025}+\dfrac{2}{2025}+\dfrac{3}{2025}+\dots+\dfrac{2024}{2025}$
答案
6. 1012
