In this tutorial we will subtract the binary number 101012 from 11102 using the borrow method.

 First, we subtract the rightmost column. 1 minus 0 equals 1. ``` 10101 - 01110 1``` In order to subtract the second column, we need to borrow a 1. So we cross out the 1 in the third column, and represent it as two 1s in the second column. ``` 1 01 10101 - 01110 1``` We can now subtract 1 from the group of two borrowed 1s. This leaves us with 1, so we write it below the second column. ``` 1 01 10101 - 01110 11``` Now we subtract the next column. Since we borrowed from this column, the subtraction is 0 minus 1 and we must borrow again. However, our next column has no 1 for us to borrow. So, we must first borrow from the last column. ``` 1 1 0101 10101 - 01110 11``` Then borrow a 1 from the fourth column into our current column. ``` 1 111 0101 10101 - 01110 11``` We can now perform the subtraction for the current column. We take 1 away from our group of two blue 1s. This leaves us with a single 1 which we write below the column. ``` 1 111 0101 10101 - 01110 111``` In the fourth column, we subtract 1 from 1 for a result of 0. ``` 1 111 0101 10101 - 01110 0111``` Our last column contains contains all zeros, so we write 0 below it. This gives us our answer of 001112. ``` 1 111 0101 10101 - 01110 00111```

Animated version