Question

represent root 5 on numberline

Answer 1

 √5 = 2.236 (Plus and Minus)
Hence we can round it up to +2.2 and -2.2
Now, in the number line we can plot this value between 2 and 3 and accurately in 2.2 place.  

Answer 2

-/5 can be represented on the no. line by using compas also
for it u need to draw a right triangle whose hypo is equal to -/5
the triangle can have 2 and 1 .
after that draw a line from 2 of 1 unit and name the point as A . now join 0 with that line .
a right triangle will be formed 
after that take a compass , put it on the point 0 and mark the distance from 0 to A
then using compass of that lenght only mark it on the number line 
this will give ur answer