## Thursday, February 7, 2008

### Thursdays Work

First, for those of you who missed yesterdays stuff. If you want to make up for it, write the following number in Wednesdays box on your homework tracking sheet:

"112358132134"
That will be your make-up.

For the homework tonight, you are supposed to finish the word problems on the back of the worksheet we were doing in class. There are some tough questions near the bottom of the page, as well as number 3.

For #3 Gear Ratio:
The question gives you the ratio of gear A to gear B as 5/12. Now you need a third number. Look at the picture to the right and you will see a picture of gear A. How many teeth does it have? Use that number as your third number and fill it into the proportion you make up.

For #9 Solar System Model:
The question gives you three number but three different sentences. It gives you the Sun, the Earth, and the size of a basketball. The correct way to set up the proportion is:
24/870000 = x/8000
Your answer will be a very small number. Which makes sense. The sun is huge! If you shrunk it to the size of the basketball, the earth would shrink way down to the size of a speck.

For #10 Painting problem:
You are given one number, 1.5 and two pictures of walls. First, figure out how big each wall is (base x height). Then, set up a proportion so you know how much paint covers the small wall. Then, solve the proportion to find out how much is needed for the big wall.

1.5/wall #1 = x/wall #2