I am very much enjoying the itty-bitty geometry in Grade 7! We have been working a lot with hands-on investigations to develop concepts around triangular areas, shearing, and square roots.
For tomorrow, since it's the end of a week, I am going to use a short discussion to re-focus their attention on the idea "What do we know? What do we NEED to know?" which I think is so key to understanding Geometry.
So, I made this powerpoint file to guide that discussion. (You have to actually play the slideshow in order to see the animations properly.) We're going to look at different basic shapes, initially without any values labeled; I'll have volunteers go up to the board to show what values we NEED to know in order to find the areas, and then I'll click the mouse to reveal a bunch of values (including extraneous info), to actually calculate the areas. The last slide will be an introduction into quadrilateral areas, which we will explore next via hands-on cutting and pasting.
(I am very happy that all of my 7th-graders are drawing rectangles around triangles to find areas, and that they are un-doing shearing in order to find areas of oblique triangles! Way to not memorize formulas!!)
Any last-minute recommendations??