25,045 how to convert it to a base ten quick draw

Question

25,045 I want to change it to a base ten quick draw

Answer 1

I have to assume that 25045 is in a base different from 10. The highest digit in the number is 5 so the base could be 6, 7, 8 or 9. I assume that it's not beyond 10. Let's start with base 9.

To convert we take the first two digits and subtract the 1st digit from the second: 25-2=23. This converts 25 in base 9 to 23 in base 10. Now we take this and bring in the next digit, 0, and subtract 23: 230-23=207. So far we've converted 250 into decimal 207. Continue the same process: 2074-207=1867; 18675-1867=16808.

Now base 8.

This time we take the first two digits and subtract twice the first digit from the second: 25-4=21. Next: 210-42=168, then 1684-336=1348; 13485-2696=10789.

Base 7.

We take the first 2 digits and subtract thrice the first from the second: 25-6=19; then 190-57=133; 1334-399=935; 9355-6550.

Base 6.

Same, but subtract 4 times: 25-8=17; 170-68=102; 1024-408=616; 6165-2464=3701.