51399 ÷ 4 = 12849 R3
Sure thing! Let's divide 51399 by 4 together.

Step 1:
4 goes into 5 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 4 from 5 to get 1.
Bring next digit (1) of the dividend behind the 1 and repeat the process: 11 / 4

Step 2:
4 goes into 11 2 times with a remainder of 3.
Write down 2 as next digit of of the result. 
Result so far: 12
Subtract 8 from 11 to get 3.
Bring next digit (3) of the dividend behind the 3 and repeat the process: 33 / 4

Step 3:
4 goes into 33 8 times with a remainder of 1.
Write down 8 as next digit of of the result. 
Result so far: 128
Subtract 32 from 33 to get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 4

Step 4:
4 goes into 19 4 times with a remainder of 3.
Write down 4 as next digit of of the result. 
Result so far: 1284
Subtract 16 from 19 to get 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 4

Step 5:
4 goes into 39 9 times with a remainder of 3.
Write down 9 as next digit of of the result. 
Result so far: 12849
Subtract 36 from 39 to get 3.

The final result is 12849 with a remainder of 3.