Hello,
I think we should turn all of these numbers to decimals so that we can tell which one is least and greatest.
Let's start with 4/25. Let's get the divide 4 by 25 to get the decimal form. 4÷25=.16
Then 13%, move the decimal two places to the left to get it into percentage form. After you move the decimal, it is now .13
0.28 is already in decimal form, let's move to the next one.
7%, again let's move the decimal place two places to the left. After that, it i now .07
21/100, let's divide "21" from "100, 21÷100= 0.21
0.15 is already in decimal form, so now we are ready to order them from least to greatest.
Least to Greatest: 0.7 (7%), 0.13 (13%), 0.15, 0.16 (4/25), and lastly 0.21 (21/100).
Hope this helps!
May