《2025年口算训练宁波出版社六年级数学上册人教版》

(一)
$\frac{7}{12} × \frac{12}{7} = $1
$\frac{5}{12} × \frac{12}{5} = $1
$\frac{5}{72} × \frac{72}{5} = $1
$2.8 × \frac{8}{7} = $3.2
$\frac{25}{63} × \frac{63}{25} = $1
$2.8 × \frac{5}{14} = $1
$2 × \frac{1}{2} = $1
$\frac{4}{25} × \frac{25}{4} = $1
$0.4 × \frac{2}{5} = $0.16
$9 × \frac{1}{9} = $1
$150 × \frac{2}{15} = $20
$1\frac{1}{9} - \frac{1}{9} = $1
$\frac{4}{15} × \frac{15}{4} = $1
$\frac{4}{11} × \frac{11}{4} = $1
$1.6 × \frac{5}{8} = $1
$\frac{4}{21} × \frac{21}{8} = $0.5
$\frac{5}{36} × 24 = $$\frac{10}{3}$
$\frac{9}{10} × \frac{5}{9} × 2 = $1
$\frac{5}{24} × 120 = $25
$\frac{1}{12} + \frac{11}{12} = $1
$0.875 × \frac{8}{7} = $1
$\frac{2}{3} × \frac{3}{2} = $1
$5 × \frac{1}{5} = $1
$0.25 × \frac{1}{4} = $0.0625

答案： 1. 1
2. 1
3. 1
4. 3.2
5. 1
6. 1
7. 1
8. 1
9. 0.16
10. 1
11. 20
12. 1
13. 1
14. 1
15. 1
16. 0.5
17. $\frac{10}{3}$
18. 1
19. 25
20. 1
21. 1
22. 1
23. 1
24. 0.0625