I am a word of six Remove the last half and I give hair to the bald. Replace the first letter with a G and I am a light, silly, or nervous laugh. All these letters being changed made me feel excited, just like your dog when they didn't see you all day...

I have numbers but no voice, I have a face but no eyes. I can help you find the sum, But when I am upside down, I can speak in words. What am I?

Contrary to what my name suggests, I don't make nor receive calls, but I -DO- sit on your noggin.

I keep information behind you. My mouths are a plenty, they bind too. The knowledge I hold, Inside, in a fold. One strap for the bold. Jansport, mind you.

First four would be something you use for any work. Next three is something you should think outside of.