Order the following set of rational numbers from least to greatest, and explain how you determined the order.
-3, 0, -1/2, 1, -3 1/3, 6, 5, -1, 21/5, 4

-3, 0, -1/2, 1, -3 1/3, 6, 5, -1, (21)/5, 4

We are going to order it from the least to the greatest.

So we would start with the negative numbers, because they are the smallest.

The largest number that has a negative sign attached is actually the smallest, so we would start with it. That is how you determine the smallest negative number.

Have assumed  (21)/5 = 4.2

-3  1/3,    -3,  -1,  -1/2 ,  0,   1,  4, (21)/5,  5 ,  6

Have assumed -3 1/3 as a mixed fraction and 21/5 to mean  21 ÷ 5.