Subtract the ones digits.

Subtract the tens digits.  There is no need to borrow a one.

Subtract the hundreds digits. 

The thousands digit will remain the same.

The answer is:  

Add the ones digits.

Add the tens digits.

The tens digit of this number will be the carryover.

Add the hundreds digits with the carryover.

The tens digit of this number will be the carryover.

Add the thousands digits with the carryover.

Combine this number with the ones digits of the other numbers.

The answer is:  

Add the ones digits.

The carryover is the tens place.

Add the tens digits with the carryover.

The carryover is the tens place.

Add the hundreds digits with the carryover.

The carryover is the tens place.

Add the thousands digits with the carryover.

Combine this number with the other three numbers from the previous calculations.

The answer is:  

Add the ones digits.

Add the tens digits with the tens digit of this number as the carryover.

The tens digit is the carryover.

Add the hundreds digits with the carryover.

Combine all the numbers.

The answer is:  

Borrow a one from the tens place of the first number.  The tens digit will become six.

Subtract the ones digits.

Subtract the tens digits.   The tens digit will become six.

Borrow a one from the thousands place in order to subtract the hundreds digits.

Subtract the hundreds digits.

The thousands place will become eight.

Combine the numbers.

The answer is:  

Add the ones digits.

The carryover is the tens place.

Add the tens digits with the number in the tens place.

Combine this number with the ones digit.

The answer is:  

Add the ones digits.

The tens place of this number is two and will be the carryover.

Add the tens digits with the carryover.

The tens place of this number is two and will be the carryover.

Add the hundreds digits with the carryover.

The tens place of this number is one and will be the carryover.

Add the thousands places with the carryover.

Combine this number with the ones digits from the previous calculations.

The answer is:  

Borrow a one from the tens digit of 915 in order to subtract the ones digits.  The tens digit of 915 becomes zero.

Borrow a one from the hundreds digit of 915 in order to subtract the tens digits.  The hundreds digit becomes an eight.

Subtract the hundreds digits.

Combine the numbers.

The answer is:  

Add the ones digits.

The tens place of this number is one, which is the carryover.

Add the tens digits with the carryover.

The tens place of this number is also one, which is the carryover.

Add the hundreds digits with the carryover.

Add the thousands digits with the carryover.

Combine all the ones digits.

The answer is:  

Add the ones digits.

Add the tens digits with the carryover, which is the tens place.

Repeat the process for the hundreds digits.

Add the thousands digits with the carryover.

Combine this number with the ones digits of the numbers from the previous calculation.

The answer is: