The Trachtenberg System's approach to subtraction is designed to avoid the mental strain of "borrowing." Instead, we transform a difficult subtraction problem into an easier addition problem using complements.
Instead of calculating , we perform and then adjust the result. This transforms subtraction into addition.
The final answer is 354.
Enter two numbers to see the complement method in action.
It's a mathematical trick. The expression 'A - B' is equivalent to 'A + (1000 - B) - 1000'. The '(1000 - B)' part is the complement, and subtracting 1000 at the end is the same as removing the leading '1'. You are temporarily adding a large, round number to make the subtraction easy, then taking it away at the end.
It's a mental math shortcut to find the complement of a number from a power of ten (like 100, 1000, etc.). You subtract every digit from 9, except for the very last non-zero digit, which you subtract from 10. It's much faster than doing the full subtraction in your head.
Yes. For the method to work perfectly, you should first pad the smaller number (the subtrahend) with leading zeros until it has the same number of digits as the larger number (the minuend). Then, you find the complement of this padded number.