Separate negatives from positives. Negatives are less than positives. The magnitude of a negative is its negativity: the bigger it looks the more negative it is, so let’s put the negatives in order first:
-4, -5/2 (same as -2½), -2.
Now convert the positives to decimals: 15%=0.15, 1/4=0.25, 1/16=0.0625. We can rewrite the decimals so that they all have the same number of decimal places: 0.1500, 0.2500, 0.0625, now they are easier to order:
0.0625, 0.1500, 0.2500; that is, 1/16, 15%, 1/4.
Answer is -4, -5/2, -2, 1/16, 15%, 1/4.