Cross hatching

I recently did a scheme of work with my year 5 class focusing on texture, tone and value.
We looked at various techniques, including cross hatching. 
I have used cross hatching in my own art, but not for a while, and never using charcoal and chalk for a portrait: so here we are.
A2 sugar paper.

I don't know who this is, the stimulus was an image from the internet.