991 ÷ 7 = 141 R4
Let's divide 991 by 7.

Step 1:
7 goes into 9 1 times with a remainder of 2.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 7 from 9 to get 2.
Bring next digit (9) of the dividend behind the 2 and repeat the process: 29 / 7

Step 2:
7 goes into 29 4 times with a remainder of 1.
Write down 4 as next digit of of the result. 
Result so far: 14
Subtract 28 from 29 to get 1.
Bring next digit (1) of the dividend behind the 1 and repeat the process: 11 / 7

Step 3:
7 goes into 11 1 times with a remainder of 4.
Write down 1 as next digit of of the result. 
Result so far: 141
Subtract 7 from 11 to get 4.

The final result is 141 with a remainder of 4.