Suppose the two digit numbers are "10A+B" and "10C+D:, then (10A+B)(10C+D) = (10B+A)(10D+C) That simplifies to AC = BD so the reason 32 x 46 = 23 x 64 is because the product of the tens digits of 32 and 46 (3x4 equals the product of the units digits 2x6). All the possibilities are below: 1. 21 × 24 = 504 and 12 × 42 = 504 2. 21 × 36 = 756 and 12 × 63 = 756 3. 21 × 48 = 1008 and 12 × 84 = 1008 4. 31 × 26 = 806 and 13 × 62 = 806 5. 31 × 39 = 1209 and 13 × 93 = 1209 6. 32 × 46 = 1472 and 23 × 64 = 1472 7. 32 × 69 = 2208 and 23 × 96 = 2208 8. 41 × 28 = 1148 and 14 × 82 = 1148 9. 42 × 12 = 504 and 24 × 21 = 504 10. 42 × 36 = 1512 and 24 × 63 = 1512 11. 42 × 48 = 2016 and 24 × 84 = 2016 12. 43 × 68 = 2924 and 34 × 86 = 2924 13. 62 × 13 = 806 and 26 × 31 = 806 14. 62 × 39 = 2418 and 26 × 93 = 2418 15. 63 × 12 = 756 and 36 × 21 = 756 16. 63 × 24 = 1512 and 36 × 42 = 1512 17. 63 × 48 = 3024 and 36 × 84 = 3024 18. 64 × 23 = 1472 and 46 × 32 = 1472 19. 64 × 69 = 4416 and 46 × 96 = 4416 20. 82 × 14 = 1148 and 28 × 41 = 1148 21. 84 × 12 = 1008 and 48 × 21 = 1008 22. 84 × 24 = 2016 and 48 × 42 = 2016 23. 84 × 36 = 3024 and 48 × 63 = 3024 24. 86 × 34 = 2924 and 68 × 43 = 2924 25. 93 × 13 = 1209 and 39 × 31 = 1209 26. 93 × 26 = 2418 and 39 × 62 = 2418 27. 96 × 23 = 2208 and 69 × 32 = 2208 28. 96 × 46 = 4416 and 69 × 64 = 4416 Edwin