Jim gets paid $10 per hour. The amount Jim gets paid in a week depends on the number of hours he works that week. How should we represent each of these quantities?
Let p represent the amount Jim gets paid in a week. Let h represent the number of hours Jim works that week. Then p = 10 · h is a formula expressing Jim's pay in terms of the number of hours he worked. Not that Jim is will make any more money now that we know this is a formula, but it certainly is good information for us to have. Get back to work, Jim.