The best way to know how numbers are ordered from least to greatest, is to place them on the number line. The number line by its construction has the least values on the left of the origin (0) and the greatest values towards the right of zero.
So imagine you have the number line with zero in the center, and the line extending to the lft and to the right.
When you place the given numers on the line, you place -5 five units (tick marks) to the left odf zero, 1 one unit to the right of zero, 3 three units to the right of zero, -2 two units to the left of zero, and finally 5 five units to the right of zero.
So, looking at the numbers we located from left to right, we find them in this order:
-5, -2, 1, 3, 5
Refer to the image to look from left to right what the order of the numbers is. The least value is -5 (marked as the first red dot on the line when you read from left to right), then -2 follows, then 1, then 3 and finally 5.