Just show me the text!
Reader View in Safari on iOS devices strips webpages of everything except text and images. On a mobile device, tap the icon on the left side of the address bar to see a white page with black text plus a button for controlling text size; tap it again to return to the original page. (Safari lets you know when Reader View is available for a page by flashing a quick "Reader View Available" message as a website is loading.) On a laptop or desktop, the full Safari app offers the same functionality, with the plus that printing or projecting is much easier for a class to read.
Some webpages don't allow Reader View; in that case, the Readability Bookmarklet could be the answer. Simply drag the bookmarklet to your address bar to use it. (There are also instructions for an iOS install.)