Let's tackle subtraction first. Subtraction in hexadecimal works similar to subtraction in decimal. Let's do a pair of decimal problems and see if we can parallel the solution method in hex. Suppose we want to subtract 1586 - 243 (in decimal).
Refraction of Light Rays. the bending or deflection of light rays as they pass through the various media of the eye that include the conjuctiva, cornea, aqueous humor, lens, and vitreous body.
Hi Bess- I'm putting up a quick answer so you'll have something to help right away in class. We may improve it as we find better illustrations, etc. I've marked your question as a follow-up to an old one that has some pictures of how light rays bend as they pass through lenses. On the second question, I think the key thing is to use lots of pictures. Draw a little figure, with rays of light coming off say the head and the foot.