Sunday, February 28, 2010
Math Class, Wednesday February 24
In math class we wrapped up problem 3.2 and started problem 3.3. In problem 3.2 we had to find Sascha's rates in miles per hour for each part of her trip. We had to figure out which part she went the fastest, and the slowest. Also you had to figure out how long it would take you to travel as far as she did in the same amount of time going 13 mph, and the last thing we had to solve was the steady rate we would have to mantain to keep up with him, and tie him. In problem 3.3 we had to compare CD prices between two different stores. We had to find out which store had a better price for each CD. We had to figure out an equation that you could use to calculate the cost for any purchase of CDs. Then, the next problem we had to solve was using the equation to write new ones including 5% tax on any purchase. On the next problem we had to figure out an equation of the cost of any order for discs on a website that cost $8.99 each with no tax, but 5$ shipping on any order. The last problem we solved was answering "How many discs do you have to order from the website to get a better deal tha buying from Music City?" and "How many discs do you have to order from the website to get a better deal than buying from CD World?". In class we also learned about rounding. We learned 5 and up, you round to the next number, but anything under 5 you keep the number the same. We learned more about rates in wrapping up 3.2, and we learned more about solving problems with tax in completing 3.3.
Friday, February 26, 2010
Thursday, February 25, 2010
Wednesday, February 24, 2010
Math Class on February 23, 2010
In class today we worked on problem 3.2 on page 35 in groups. It shows at the top of the page how far Sascha traveled by bike after certain amounts of time. He stopped 3 times to record his time and distance. By stop 1 he had gone 5 miles in 20 minutes. 5/20 =15/60, which means 15 miles in 60 minutes, or 1 hour. This means he went 15 MPH for the first portion of the ride. By the second stop he had went 8 miles in 24 minutes. 8/24= 1/3= 20/60. That means 20 miles in 60 minutes, or 20 MPH. For the last one he went 15 miles in 40 minutes. 15/40= 22.5/60. That means 22.5 miles in 60 minutes, or 22.5 MPH. It is also okay to put the minutes as the numerator and the miles as the denominator. As you can tell, Sascha traveled the fastest at the third stop, and slowest at the first stop. If you were going 13 MPH on a bike it would take you 2 hours and 9 minutes to travel as far as Sascha did. Sascha traveled 28 miles (15+5+8). Our group decided to figure out how long it would take us to travel 1 mile going 13 MPH. 60/13=4.6. Since this is how long it would take us to travel 1 mile, we then multiply 4.6 by 28. 4.6*28=129.23. Then we divided that by 60 and got 2.15. The .15 represents 15/100 which equals 6/60, or 2 hours and 9 minutes. To find Sascha's steady rate, you find his average speed by adding 15+20+ 22.5=57.5. Divide this by 3 to find the average speed.
Tuesday, February 23, 2010
Monday, February 22, 2010
Saturday, February 6, 2010
Yesterday in math class we did the orange juice problem. In this unit we have been using fractions, ratios, differences, and percents and these played a big part in this problem.
One thing we had to do in the problem is found out how many bathches we would need to make for 240 campers if each camper got 1/2 glass. For one off the problems there were 2 cups of concentrate and 3 cups of water and we found that to make 120 cups we would need t make 24 batches. We found this by doing 2 and 3 makes 5 and 5x24 =120. Another thing we had to do with this problem is if the ratio is 5 (cups of concentrate) to 9 (cups of water) and we need to find what fraction of the mix is water it would be 9/14 not 9/5. For mix A to find the cups of water and concentrate you multiply 2 (concentrate) by 24 which equals 48. Then you multiply 3 (water) by 24 again and get 72. This just scratches the surface of this problem and hopefully it helped.
One thing we had to do in the problem is found out how many bathches we would need to make for 240 campers if each camper got 1/2 glass. For one off the problems there were 2 cups of concentrate and 3 cups of water and we found that to make 120 cups we would need t make 24 batches. We found this by doing 2 and 3 makes 5 and 5x24 =120. Another thing we had to do with this problem is if the ratio is 5 (cups of concentrate) to 9 (cups of water) and we need to find what fraction of the mix is water it would be 9/14 not 9/5. For mix A to find the cups of water and concentrate you multiply 2 (concentrate) by 24 which equals 48. Then you multiply 3 (water) by 24 again and get 72. This just scratches the surface of this problem and hopefully it helped.
Friday, February 5, 2010
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