Subtraction-fest 05 ~ Floating Digit Variation (Subtracting From Powers of Ten)

This (fifth) subtraction method is a variation earlier methods, but deals with the special case when we subtract numbers from powers of ten ... such as 100, 1000 or 1 000 000.

Because the borrowing method would leave a string of "9s" and a final "10" on the top line (after borrowing from the initial "1"), we simply subtract all the leading digits from nine, and the final digit from ten. That is all there is to it!

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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]

Just as you said, this is a special case of "Floating Digit" method. Nevertheless, I find it immensely enjoyable ! Thank you for showing us entertaining borderline cases.

[Ensign_Cthulhu]

Subtract them all from nine. Then add one.