Tuesday, November 2, 2010

Princess' scribepost for November 2, 2010

Today in class, we were each assigned a question for the blog. I'll be doing question 20a, and b.

20a) Kwasi said that he ignored the fractions when he decided that -2 1/5 is smaller than -1 9/10. Explain his thinking.

Well, if you pretend the fractions aren't there and just take a look at the whole numbers they would be -2 and -1. Now, since -2 would be on the left side of -1 on a number line, it would be smaller.

If you put the fractions back, it wouldn't make a difference because the whole numbers would still be the same.
Answer: -1 > -2

b) Naomi said that she ignored the integers -1, when she decided that -1 1/4 is greater than -1 2/7. Explain her thinking.

Since both start with the integer -1, it wouldn't really help if you're trying to figure out, which is greater or which is smaller. So, you just have to focus on the fractions, 1/4 and 2/7. Now, there are many ways of figuring which is greater, but I will show you one way. I'll convert them to decimals by using long division, then compare them.
1/4 = 0.25

2/7 = 0.29

Now that we know 1/4 = 0.25 and 2/7 = 0.29, we cant tell that 2/7 is bigger, but because it's a negative, it's the opposite of that. So, that means -1/4 is bigger than -2/7. If you put the integers back, it wouldn't make a difference, since they are the same, and only the fractions matter in this case.
Answer: -1 1/4 > -1 2/7

(p.s. sorry if it's not colourful, it won't work.)

1 comment:

  1. Hey princess! Boy was your blogpost ever exciting and full of easy, simple, yet so much understable information. Uhm, i would have to say that the math pictures with your explanations tied in really well. So great job ! Uhm, the colors werent bad so dont worry about it. But heres a tip um, you can change the text into making things (the numbers) appear as real fractions instead of it having to be side by side like this 2/4. So yeah just heck the html codes, but good job! ITS AMAZING!