The least number should always start off with negatives if there are any. In this case there is so we can start with -2 as our least amount. Next are the small fractions. If you're allowed a calculator, I would use that to find what the decimals will look like for each fraction:
After -2 the next least number is 0 and the next one is the fraction or decimal closest to the number 0 which is 0.4
The next number would be from the fractions we solved earlier. 0.5 and 0.625 would follow 0.4 and then 1.1 and 1.6667(solved for from fraction).