三年级的数学怎么回答？

今晚的数学题：

How can you use the digits 6 and 4 to decide if 64 is the pruduct of 9 and 7?

不知道这道题是考什么，9和7的PRUDUCT不是63吗？和64有什么关系？

所有跟帖： 

• If 64 or any number is a multiple of 9, the digits will sum to a -Lily3- ♀ (145 bytes) () 11/19/2012 postreply 17:42:18

• Or you can say that any multiple of 9 can be divided by 3. -2544- ♀ (0 bytes) () 11/19/2012 postreply 17:57:34

• 回复：三年级的数学怎么回答？ -calligraphy- ♂ (142 bytes) () 11/19/2012 postreply 17:44:24

• Because 6+4 not= 9. -粮油- ♀ (77 bytes) () 11/19/2012 postreply 18:23:27