《2025年文墨小学数学口算心算天天练五年级下册人教版》

① $\frac{4}{9} × \frac{9}{16} =$

答案： $\frac{4 × 9}{9 × 16} = \frac{4}{16} = \frac{1}{4}$

② $\frac{2}{3} × \frac{3}{8} =$

答案： $\frac{2 × 3}{3 × 8} = \frac{2}{8} = \frac{1}{4}$

③ $\frac{7}{8} + \frac{3}{14} =$

答案： $\frac{7}{8} = \frac{49}{56}$，$\frac{3}{14} = \frac{12}{56}$，$\frac{49}{56} + \frac{12}{56} = \frac{61}{56}$

④ $\frac{1}{3} - \frac{1}{3} =$

答案： $0$，相同的两个数相减差为0

⑤ $\frac{9}{10} × \frac{4}{9} =$

答案： $\frac{9 × 4}{10 × 9} = \frac{4}{10} = \frac{2}{5}$

⑥ $\frac{1}{2} - \frac{1}{3} =$

答案： $\frac{1}{2} = \frac{3}{6}$ $\frac{1}{3} = \frac{2}{6}$，$\frac{3}{6} - \frac{2}{6} = \frac{1}{6}$

⑦ $\frac{5}{21} × \frac{7}{10} =$

答案： $\frac{5 × 7}{21 × 10} = \frac{35}{210} = \frac{1}{6}$

⑧ $\frac{3}{14} + \frac{1}{2} =$

答案： $\frac{1}{2} = \frac{7}{14}$，$\frac{3}{14} + \frac{7}{14} = \frac{10}{14} = \frac{5}{7}$

⑨ $\frac{1}{12} + \frac{1}{3} =$

答案： $\frac{1}{3} = \frac{4}{12}$，$\frac{1}{12} + \frac{4}{12} = \frac{5}{12}$

⑩ $\frac{7}{8} + \frac{3}{11} + \frac{1}{8} =$

答案： $\frac{7}{8} + \frac{1}{8} = 1$，$1 + \frac{3}{11} = \frac{14}{11}$

⑪ $5 × \frac{4}{11} =$

答案： $\frac{5 × 4}{11} = \frac{20}{11}$

⑫ $\frac{7}{9} × \frac{7}{9} =$

答案： $\frac{7 × 7}{9 × 9} = \frac{49}{81}$

⑬ $(\frac{2}{3} + \frac{4}{5}) × 15 =$

答案： $\frac{2}{3} × 15 = 10$，$\frac{4}{5} × 15 = 12$，$10 + 12 = 22$

⑭ $\frac{6}{7} - (1 - \frac{3}{14}) =$

答案： $1 - \frac{3}{14} = \frac{11}{14}$，$\frac{6}{7} = \frac{12}{14}$，$\frac{12}{14} - \frac{11}{14} = \frac{1}{14}$

⑮ $\frac{1}{5} × \frac{2}{3} =$

答案： $\frac{1 × 2}{5 × 3} = \frac{2}{15}$

⑯ $\frac{5}{12} + \frac{17}{60} =$

答案： $\frac{5}{12} = \frac{25}{60}$，$\frac{25}{60} + \frac{17}{60} = \frac{42}{60} = \frac{7}{10}$

⑰ $\frac{3}{4} × \frac{8}{11} =$

答案： $\frac{3 × 8}{4 × 11} = \frac{24}{44} = \frac{6}{11}$

⑱ $\frac{3}{4} - \frac{3}{8} =$

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

⑲ $\frac{1}{2} + \frac{5}{6} =$

答案： $\frac{1}{2} = \frac{3}{6}$，$\frac{3}{6} + \frac{5}{6} = \frac{8}{6} = \frac{4}{3}$

⑳ $\frac{5}{6} × \frac{1}{2} =$

答案： $\frac{5 × 1}{6 × 2} = \frac{5}{12}$

㉑ $\frac{7}{10} + \frac{7}{15} =$

答案： $\frac{7}{10} = \frac{21}{30}$，$\frac{7}{15} = \frac{14}{30}$，$\frac{21}{30} + \frac{14}{30} = \frac{35}{30} = \frac{7}{6}$

㉒ $25 × (\frac{2}{5} - \frac{1}{3}) =$

答案： $\frac{2}{5} - \frac{1}{3} = \frac{6}{15} - \frac{5}{15} = \frac{1}{15}$，$25 × \frac{1}{15} = \frac{25}{15} = \frac{5}{3}$