## Saturday, November 14, 2009

### How I stopped an Alien Invasion using Proportion

Page 67: Question 10
Set up a proportion for each situation.

a) If 10 beans have a mass of 17 g, then 30 beans have a mass of 51 g.

I got the answer by finding out 10 times 3 is 30 and got the proportion.

b) There are 13 boys for 15 girls in every classroom at Albany Middle School. If there are 65 boys in the school, then there are 75 girls.

I got the answer by getting 13 time 65 to get 5 to get the proportion.

c) On a map, 1 cm represents 25 km. Kendra wants to ride her bike 160 km. This distance is 6.4 cm on the map.

I got the answer by finding out 1 times 6.4 equals 6.4 and getting the proportion.

Page 67 question 11:
A small gear turns 18 times in the same time that a large gear turns 4 times. How many times will the large gear turn if the small gear turns 54 times? Draw a diagram to help set up a proportion and solve the problem.

I got the answer by dividing 18 by 54 to get 0.333... so i times 4 by 0.333.... and got 12.

Page 68 Question 13. Two quarters have the same value as ten nickels. What is the value of five quarters in nickels?

I got the answer by finding out the relation with 2 and 5 was 2.5 so I times 10 by 2.5 to get 25.

Alien Story:
One day a guy who was obsessed with math was visited one day by an alien. The alien said that he would destroy earth. Right at that moment the man ran away from the alien and came back 5 hours later. He said he had just done everything he wanted to do in life and was ready to die. Then the alien just gave him a weird look and said he just wasted his time doing that. The alien said he wasn't finished talking and continued. He said that if could help him with his math homework he'll leave earth alone. He only had 3 questions left to do. He looked at the alien and said your an idiot this is 8th grade math. The alien knocked him out and the man woke up an hour later. The alien said that if he had to wait any longer he would blow the place up already. So the man said okay i'll do your homework. The alien handed over his notebook. The man saw the 3 questions and answered them. Then the alien said thanks and I won't blow up the earth. Then he waved goodbye to him and disappeared.