40309 ÷ 7 = 5758 R3
Alright, let's work through the division of 40309 by 7 step by step.

Step 1:
7 goes into 4 0 times with a remainder of 4.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 4 to get 4.
Bring next digit (0) of the dividend behind the 4 and repeat the process: 40 / 7

Step 2:
7 goes into 40 5 times with a remainder of 5.
Write down 5 as next digit of of the result. 
Result so far: 5
Subtract 35 from 40 to get 5.
Bring next digit (3) of the dividend behind the 5 and repeat the process: 53 / 7

Step 3:
7 goes into 53 7 times with a remainder of 4.
Write down 7 as next digit of of the result. 
Result so far: 57
Subtract 49 from 53 to get 4.
Bring next digit (0) of the dividend behind the 4 and repeat the process: 40 / 7

Step 4:
7 goes into 40 5 times with a remainder of 5.
Write down 5 as next digit of of the result. 
Result so far: 575
Subtract 35 from 40 to get 5.
Bring next digit (9) of the dividend behind the 5 and repeat the process: 59 / 7

Step 5:
7 goes into 59 8 times with a remainder of 3.
Write down 8 as next digit of of the result. 
Result so far: 5758
Subtract 56 from 59 to get 3.

The final result is 5758 with a remainder of 3.