Subtraction-fest 03 ~ Floating Digit Method (Change all Subtractions to Additions!)

This (third) method uses a concept that is used in designing computers. Since computer circuits can only add, in the ALU (Arithmetic Logic Unit), all subtractions are converted to additions using a 'complement' method.

Using our base ten number system, we also create a complementary number ... and it is so easy that you can learn to complete this step very quickly indeed! All that remains is to ADD the complementary number (and remove the 'floating digit').

This is not a method that I would teach to children as their primary method for subtracting numbers, but it is a rather 'fun' and ununsual method that I hope will appeal to you.

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RATIONALE FOR THIS SERIES

Some of you have expressed quite some interest in different subtraction methods/algorithms. This resulted from my posting two lengthy videos in which I explained WHY different algorithms worked.

It became apparent, however, that I needed to create a series of much shorter videos in order to DEMONSTRATE these methods (and more) without the lengthy explanations in those first two videos.

[MrVoayer]

This "10's Complement" method may not seem "natural" to uninitiated, but I find it so amusing and funny. And because addition is always thought first and because, to most people, addition is easier than subtraction, converting subtraction to addition should cheer up a lot of spectators.Great job, Greame !