Explanation:
1.
2×sqrt(10) = 6.32455532...
sqrt(36) = 6
2 2/5 = (10 + 2)/5 = 12/5 = 2.4
6.1222222222...
so, the order
2 2/5 6 6.12222... 6.32455...
3.
-sqrt(25) = -5
-4.2
sqrt(5)/6 = 0.372677996...
7/2 = 3.5
so, the order
-sqrt(25) -4.2 7/2 sqrt(5)/6
5.
the numbers are all there already.
so, the order
-3.1 -2.1 1.4 2.7
when you look at the number lines, when your mark the numbers, you will see it clearly.
be careful with the negative numbers : "bigger" is actually smaller (more to the left).
-4.2 is left of -4 ! going in the directing of -5.
-3.1 is left of -3 ! going in the direction of -4.
-2.1 is left of -2 ! going in the direction of -3.