Hints, tips and best practices for teaching math online from a community college professor

1. Tips and Tricks for Teaching Math Online By Fred Feldon Coastline Community College Fountain Valley, CA April 29, 2008

12. Answer: 5 th Square No. 4 th Triangular No. n th Square No. n -1 Triangular No. n 2 + 4[ n ( n - 1)/2] = 3 n 2 - 2 n n th Star No. 400 + 4(190) = 1,160 20 th Star No. 25 + 4(10) = 55 5 th Star No. 16 + 4(6) = 40 4 th Star No. 9 + 4(3) = 21 3 rd Star No. 4 + 4(1) = 8 2 nd Star No. 1 1 st Star No.

13. A Fly in the Room Two walls and the ceiling of a room meet at right angles at point P. A fly is in the air one foot from one wall, eight feet from the other wall, and nine feet from point P. How many feet is the fly from the ceiling?

15. Arc To Area The arc below has a measure of 40 degrees, and its endpoints are at (1,5) and (5,3). Find the area of the circle that contains the arc.

16. Answer To find the answer you don’t need to know where the center is, you just have to find the radius. Draw a picture, put a point about where the center might be, draw a triangle, label everything you know and go from there. You can use the Law of Sines or split the triangle in two (a 20-90-70 triangle) and use trig to get the length of the radius, about 6.5382, so the area of the circle is about 134.28 square units .

17. Mathematical Misfit Which fits best: a square peg in a round hole, or a round peg in a square hole? To be more precise, if you take a circle and fit it just inside a square, or take a square and fit it just inside a circle, which fills up proportionally the most space?

18. Answer: Take a Square whose side = 1 unit, and a circle which just fits inside. Area of Circle/Area of Square = (1/2) 2 / 1 = /4 = 0.785. Take a Circle whose diameter = 1 unit, and a square which just fits inside. Area of Square/Area of Circle = (1/ ) 2 / ( (1/2) 2 ) = 2/ = 0.637. Since /4 > 2/ , the round peg fills up proportionally more space and therefore fits better in the square hole than the square peg fits in the round hole!

19. The Shrinking Watermelon Yesterday you bought a huge 100-pound watermelon that was 90% water. You left it outside in the hot sun. Some of the water evaporated, so it is now 80% water. How much does it weigh now?

20. Answer The 10 pounds of fruit that didn’t evaporate is still there. That now must represent 20%, or one-fifth, of the shrunken watermelon. So the watermelon must weigh 50 pounds .

21. From Images of Mathematicians on Postage Stamps: The Impossible Figures of Oscar Reutersvard , Sweden, 1982

30. Recent Time magazine article: Subjects in an experiment did math problems and made fewer errors with a pet in the room, compared to with their friends, their spouse, or alone!

31. “ On the Internet, nobody knows you’re a dog!”

32. Adapting to Technology

33. Adapting to Technology

34. Adapting to Technology

41. Supplement the Course With Your Own Material (Con’t) See actual video at: http://web.ccc.cccd.edu:8080/ramgen/2/math/math100_calculator.smil