He could mean base 2. So 60,000*2^2=240,000
However, I am not a mathematician. I don't know that base -2 complies with the laws of mathematics.
Improvements for negative exponent version 2.0 - any loss can now be called exponential growth by selecting the appropriate exponent.
value = 0;
for(i = 0; i < numberOfDigits; i++)
value += n^i + number[i];
Or, it looks like a(n^2) + b(n^1) + c*(n^0).So, if you have a base less than 1, you get smaller as you go to the left.
Also, if you have a negative base, you change from adding to subtracting every digit. In a sort of "That'll take 2 years, minus 4 months, plus 2 weeks, minus 3 days" sort of way.