214-216, pg. 181. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/test-prep/gmat/problem-solving/v/gmat-math-46?utm_source=YT&utm_medium=Desc&utm_campaign=GMAT Missed the previous lesson? https://www.khanacademy.org/test-prep/gmat/problem-solving/v/gmat-math-44?utm_source=YT&utm_medium=Desc&utm_campaign=GMAT GMAT on Khan Academy: Sal works through the 249 problem solving questions in chapter 5 of the the 11th edition of the official GMAC GMAT Review (ISBN Number: 0-9765709-0-4 published in 2005) About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. ... https://www.youtube.com/watch?v=o0azgDKAFNI Note: All Khan Academy content is available for free at (www.khanacademy.org)

Again, some quadrilaterals can be oddly shaped so break it up into shapes where finding the area is more easily determined. Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-geometry-topic/cc-6th-area-shapes-grid/e/area-of-triangles-2?utm_source=YT&utm_medium=Desc&utm_campaign=6thgrade Watch the next lesson: https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-geometry-topic/cc-6th-area/v/area-of-a-trapezoid-1?utm_source=YT&utm_medium=Desc&utm_campaign=6thgrade Missed the previous lesson? https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-geometry-topic/cc-6th-area-shapes-grid/v/area-of-triangle-in-grid?utm_source=YT&utm_medium=Desc&utm_campaign=6thgrade Grade 6th on Khan Academy: By the 6th grade, you're becoming a sophisticated mathemagician. You'll be able to add, subtract, multiply, and divide any non-negative numbers (including decimals and fractions) that any grumpy ogre throws at you. Mind-blowing ideas like exponents (you saw these briefly in the 5th grade), ratios, percents, negative numbers, and variable expressions will start being in your comfort zone. Most importantly, the algebraic side of mathematics is a whole new kind of fun! And if that is not enough, we are going to continue with our understanding of ideas like the coordinate plane (from 5th grade) and area while beginning to derive meaning from data! (Content was selected for this grade level based on a typical curriculum in the United States.) ... https://www.youtube.com/watch?v=gkifo46--JA Note: All Khan Academy content is available for free at (www.khanacademy.org)

Example constructing formaldehyde Lewis diagram ... https://www.youtube.com/watch?v=s0VM7WKnPeA Note: All Khan Academy content is available for free at (www.khanacademy.org)

Comparing decimals in different representations ... https://www.youtube.com/watch?v=_tk3nWC5OAA Note: All Khan Academy content is available for free at (www.khanacademy.org)