12459 ÷ 7 = 1779 R6
Alright, let's work through the division of 12459 by 7 step by step.

Step 1:
7 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 1 to get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 7

Step 2:
7 goes into 12 1 times with a remainder of 5.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 7 from 12 to get 5.
Bring next digit (4) of the dividend behind the 5 and repeat the process: 54 / 7

Step 3:
7 goes into 54 7 times with a remainder of 5.
Write down 7 as next digit of of the result. 
Result so far: 17
Subtract 49 from 54 to get 5.
Bring next digit (5) of the dividend behind the 5 and repeat the process: 55 / 7

Step 4:
7 goes into 55 7 times with a remainder of 6.
Write down 7 as next digit of of the result. 
Result so far: 177
Subtract 49 from 55 to get 6.
Bring next digit (9) of the dividend behind the 6 and repeat the process: 69 / 7

Step 5:
7 goes into 69 9 times with a remainder of 6.
Write down 9 as next digit of of the result. 
Result so far: 1779
Subtract 63 from 69 to get 6.

The final result is 1779 with a remainder of 6.