登录
1.直接写出得数。(每题1★)
$\frac{1}{6}+\frac{5}{6}=$ $\frac{3}{7}+\frac{1}{3}=$ $\frac{3}{4}-0.5=$ $1-\frac{7}{12}=$
$\frac{3}{5}-\frac{1}{15}=$ $\frac{7}{11}+\frac{4}{11}=$ $\frac{3}{11}-\frac{3}{22}=$ $0.25-\frac{1}{7}=$
$\frac{1}{6}+\frac{5}{6}=$ $\frac{3}{7}+\frac{1}{3}=$ $\frac{3}{4}-0.5=$ $1-\frac{7}{12}=$
$\frac{3}{5}-\frac{1}{15}=$ $\frac{7}{11}+\frac{4}{11}=$ $\frac{3}{11}-\frac{3}{22}=$ $0.25-\frac{1}{7}=$
答案
1.$1$ $\frac{16}{21}$ $\frac{1}{4}$ $\frac{5}{12}$ $\frac{8}{15}$ $1$ $\frac{3}{22}$ $\frac{3}{28}$
2.计算下面各题,能简算的要简算。(每题4★)
$\frac{8}{9}+\frac{4}{11}+\frac{1}{9}$
$\frac{1}{4}+\frac{2}{5}-\frac{3}{10}$
$\frac{17}{20}-(\frac{2}{5}+\frac{9}{20})$
$8-\frac{4}{27}-\frac{23}{27}$
$6.12+\frac{1}{4}+0.75-3.12$
$\frac{1}{4}+(3-\frac{5}{4}+\frac{1}{6})$
$\frac{8}{9}+\frac{4}{11}+\frac{1}{9}$
$\frac{1}{4}+\frac{2}{5}-\frac{3}{10}$
$\frac{17}{20}-(\frac{2}{5}+\frac{9}{20})$
$8-\frac{4}{27}-\frac{23}{27}$
$6.12+\frac{1}{4}+0.75-3.12$
$\frac{1}{4}+(3-\frac{5}{4}+\frac{1}{6})$
答案
2.$1\frac{4}{11}$ $\frac{7}{20}$ $0$ $7$ $4$ $2\frac{1}{6}$
识别出错
答案
3.(1)$(8×3+8×5+3×5)×2=158(\mathrm{cm}^2)$
(2)$9×9×6=486(\mathrm{dm}^2)$
(3)$(10×6+10×6.5+6×6.5)×2-4×(10-5)×2=288(\mathrm{cm}^2)$
(2)$9×9×6=486(\mathrm{dm}^2)$
(3)$(10×6+10×6.5+6×6.5)×2-4×(10-5)×2=288(\mathrm{cm}^2)$
1. $\frac{5}{12}$ m比(
$\frac{1}{2}$
)m少$\frac{1}{12}$ m；$\frac{6}{7}$ t比($\frac{17}{28}$
)t多$\frac{1}{4}$ t。答案
1.$\frac{1}{2}$ $\frac{17}{28}$
2.一个长方体，长8 cm，宽6 cm，高4 cm。它的棱长总和是(
72
)cm，表面积是(208
)cm²。答案
2.72 208
3.一堆沙子的总质量为2.8 t，第一次用去$\frac{1}{4}$ t，第二次用去$\frac{11}{20}$ t，两次共用去(
$\frac{4}{5}$
)t，还剩这堆沙子的($\frac{5}{7}$
)。答案
3.$\frac{4}{5}$ $\frac{5}{7}$
