Question

Half of a number is greater than or equal to 10.”

Answer 1

1/2x>=10
(That's supposed to be a greater than or equal to sign)

That's your inequality. To solve:
x>=20
Now, your number line should have a dot on 20 that is colored in since it can be equal to 20. Then, draw a line extending from 20 to the right of 20 with an arrow since x can be greater than 20.

Answer 2

I'd transcribe the word problem directly into an inequality, as follows:

(1/2)n is greater than or equal to 10.  Mult. both sides by 2 results in

"n is greater than or equal to 20" (answer)

Draw a horiz. number line to represent n.  Place a solid dot at x = 20.  Draw an arrow from n=20 to the right.  That's it.