Special-cased algorithm to divide by 2 in base 10. With a hint to an extended version that works on arbitrary radix

fast decimal div2.md

divide each digit by 2 starting from the MSD using int div, if you have remainder it means you have to add 5 to the next digit AFTER dividing it by 2.

Examples:

0. 1687
1. 1/2 = 0, carry 5 because odd
2. 6/2 = 3, 3+5 = 8
3. 8/2 = 4
4. 7/2 = 3, carry 5
5. 0/2 = 0, 0+5 = 5

result is: 843.5

This algorithm could be extended to other bases/radices: Whenever you want to divide a radix B numeral by d, and d is a factor of B, the extended algorithm can speed-up division. The actual implementation is left as an excercise to the reader ;) lol