Whatever you want, of course. Here is the answer: ‘1467’
The right math riddle here is that all beans have to be divided by the number of boxes so by ‘4’. The first bean is 687 and that divided by 4 equals 171,75 (aka the fourth bean). Then 171,75 divided by four equals 42,94 (the sixth bean). Last but not least 42,94 divided by 4 equals 10,73 (the seventh bean).