《2025年文墨小学数学口算心算天天练五年级下册人教版》

① $(\frac{3}{14} + \frac{4}{7}) × 35 =$

答案： $\frac{4}{7} = \frac{8}{14}$，$\frac{3}{14} + \frac{8}{14} = \frac{11}{14}$，$\frac{11}{14} × 35 = \frac{385}{14} = \frac{55}{2}$

② $\frac{1}{20} + \frac{7}{10} × \frac{5}{6} =$

答案： $\frac{7}{10} × \frac{5}{6} = \frac{35}{60} = \frac{7}{12}$，$\frac{1}{20} + \frac{7}{12} = \frac{3}{60} + \frac{35}{60} = \frac{38}{60} = \frac{19}{30}$

③ $(\frac{2}{5} + \frac{1}{5}) × 45 =$

答案： $\frac{2}{5} + \frac{1}{5} = \frac{3}{5}$，$\frac{3}{5} × 45 = 27$

④ $\frac{11}{23} + \frac{23}{47} × 0 =$

答案： $\frac{23}{47} × 0 = 0$，$\frac{11}{23} + 0 = \frac{11}{23}$

⑤ $12 × (\frac{1}{8} + \frac{3}{4}) =$

答案： $\frac{3}{4} = \frac{6}{8}$，$\frac{1}{8} + \frac{6}{8} = \frac{7}{8}$，$12 × \frac{7}{8} = \frac{84}{8} = \frac{21}{2}$

⑥ $\frac{1}{8} × \frac{2}{5} × \frac{5}{7} =$

答案： $\frac{2}{5} × \frac{5}{7} = \frac{10}{35} = \frac{2}{7}$，$\frac{1}{8} × \frac{2}{7} = \frac{2}{56} = \frac{1}{28}$

⑦ $(\frac{1}{6} - \frac{1}{8}) × 24 =$

答案： $\frac{1}{6} × 24 = 4$，$\frac{1}{8} × 24 = 3$，$4 - 3 = 1$

⑧ $72 × (\frac{1}{8} + \frac{1}{9}) =$

答案： $72 × \frac{1}{8} = 9$，$72 × \frac{1}{9} = 8$，$9 + 8 = 17$

⑨ $(\frac{3}{4} - \frac{1}{8}) × 32 =$

答案： $\frac{3}{4} × 32 = 24$，$\frac{1}{8} × 32 = 4$，$24 - 4 = 20$

⑩ $(\frac{1}{4} - \frac{1}{6}) × 48 =$

答案： $\frac{1}{4} × 48 = 12$，$\frac{1}{6} × 48 = 8$，$12 - 8 = 4$

⑪ $68 × (\frac{19}{34} - \frac{7}{17}) =$

答案： $\frac{7}{17} = \frac{14}{34}$，$\frac{19}{34} - \frac{14}{34} = \frac{5}{34}$，$68 × \frac{5}{34} = 10$

⑫ $80 × (\frac{5}{6} - \frac{2}{5}) =$

答案： $\frac{5}{6} - \frac{2}{5} = \frac{25}{30} - \frac{12}{30} = \frac{13}{30}$，$80 × \frac{13}{30} = \frac{1040}{30} = \frac{104}{3}$

⑬ $\frac{7}{10} × \frac{3}{10} × 10 =$

答案： $\frac{7}{10} × 10 = 7$，$7 × \frac{3}{10} = \frac{21}{10}$

⑭ $\frac{3}{14} × 28 + 56 × \frac{9}{14} =$

答案： $\frac{3}{14} × 28 = 6$，$56 × \frac{9}{14} = 36$，$6 + 36 = 42$

⑮ $\frac{2}{3} × \frac{1}{3} + \frac{5}{9} =$

答案： $\frac{2}{3} × \frac{1}{3} = \frac{2}{9}$，$\frac{2}{9} + \frac{5}{9} = \frac{7}{9}$

⑯ $\frac{1}{2} + \frac{8}{21} × \frac{1}{2} =$

答案： $\frac{8}{21} × \frac{1}{2} = \frac{4}{21}$，$\frac{1}{2} + \frac{4}{21} = \frac{21}{42} + \frac{8}{42} = \frac{29}{42}$

⑰ $\frac{4}{5} × \frac{5}{8} + \frac{1}{4} =$

答案： $\frac{4}{5} × \frac{5}{8} = \frac{20}{40} = \frac{1}{2}$，$\frac{1}{2} + \frac{1}{4} = \frac{2}{4} + \frac{1}{4} = \frac{3}{4}$

⑱ $(\frac{2}{5} - \frac{1}{4}) × 40 =$

答案： $\frac{2}{5} × 40 = 16$，$\frac{1}{4} × 40 = 10$，$16 - 10 = 6$

⑲ $\frac{4}{9} × \frac{1}{2} + \frac{11}{36} =$

答案： $\frac{4}{9} × \frac{1}{2} = \frac{2}{9} = \frac{8}{36}$，$\frac{8}{36} + \frac{11}{36} = \frac{19}{36}$

⑳ $24 × \frac{5}{21} × \frac{3}{4} =$

答案： $24 × \frac{3}{4} = 18$，$18 × \frac{5}{21} = \frac{90}{21} = \frac{30}{7}$

㉑ $\frac{7}{13} + \frac{16}{17} × 0 =$

答案： $\frac{16}{17} × 0 = 0$，$\frac{7}{13} + 0 = \frac{7}{13}$

㉒ $45 × \frac{1}{9} × \frac{2}{5} =$

答案： $45 × \frac{1}{9} = 5$，$5 × \frac{2}{5} = 2$