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# Multiplication using antidigits

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### Multiplication using antidigits

1. 1. Multiplication using anti-digits. David Coulson, 2014
2. 2. This approach attempts to ‘simplify’ the classic paper-and-pen method of multiplication by introducing what I call anti-digits.
3. 3. This approach attempts to ‘simplify’ the classic paper-and-pen method of multiplication by introducing what I call anti-digits. For example, 46 becomes 50-4 and 68 becomes 70-2.
4. 4. This approach attempts to ‘simplify’ the classic paper-and-pen method of multiplication by introducing what I call anti-digits. For example, 46 becomes 50-4 and 68 becomes 70-2. Using this notation it is hoped that (in certain cases at least) the work done will be easier, simply because the unitary digits are all less than or equal to 5.
5. 5. This approach attempts to ‘simplify’ the classic paper-and-pen method of multiplication by introducing what I call anti-digits. For example, 46 becomes 50-4 and 68 becomes 70-2. Using this notation it is hoped that (in certain cases at least) the work done will be easier, simply because the unitary digits are all less than or equal to 5. As it turns out, the process is not generally easier, but the process may have some academic interest to some readers.
6. 6. Here’s what the classic procedure produces. The process is very much ‘bottom-up’, meaning that it starts with the smallest component and builds up to the largest component. All components are added together, and it is only at the end that the writer has any genuine notion of how big the answer is.
7. 7. This is what the alternative looks like.
8. 8. The double-negative ‘8’ becomes a positive ‘8’.
9. 9. The problems start here: Putting the four components together requires a mix of additions and subtractions. Ultimately this is more difficult than the additions of the classic approach. However, some modification of this process may prove to be useful.
10. 10. [end] dtcoulson@gmail.com