Monday, February 22, 2010

G2 kids are blogging

I found a new blog site yesterday, at kidblog.org, which lets the students each have their own blog page in a safe and structured way without having to submit an email address. Hopefully we will start using it to publish some of our writing and thinking about what we are learning. If you click on the first link under "Links to Learning" it will take you there.

I am excited about this new tool because it allows me to give opportunity for the students to blog without them having to have an insecure email adress, without me having to give them access to my email address and it allows me the ability to oversee all posts before they are published.

Thursday, February 18, 2010

Comparing Fractions

When compare fractions we are seeing if the are the same size or a different size.
We use the signs < (less than) >(greater than) =(equal to)

We have a nice easy trick to doing this.


1/4 is less than, greater than or equal to 2/3


1/4 is < > = 2/3

1/4 2/3 to find out, multiply the denominator of one fraction by the numerator of the other fraction. Do this to both fractions. Put the answer at the top of each fraction.

1/4 and 2/3
multiply 1x3 = 3 put that above 1/4
multiply 4 x 2 = 8 put that above 2/3
now compare 3 and 3
3 is less than 8
SO
1/4 < 2/3
1/4 is less than 2/3
video

Equivalent Fractions

Equiva lent mean equal, so equivalent fractions are equal fractions.

1/2
Equivalent fractions for one-half are easy, because the numerator is half of the denominator.

1/2 - 1 is half of 2
2/4 - 2 is half of 4
4/8 - 4 is half of 8
10/20 - 10 is half of 20
SO
1/2 = 2/4 = 4/8 = 10/20

Here is a song we learned to help us find equivalents of other fractions.
(to the tune of "Are You Sleeping?)

Equivalent Fractions
Equivalent Fractions
Multiply
Or Divide
By another Fraction
By another Fraction
Equal to One
Equal to One

To find an equivalent fraction, you need to multiply by a fraction equal to one.
Fractions equal to one are 2/2 3/3 4/4 5/5 6/6 ...etc.


So to find an equivalent fraction for 2/3, multiply 2/3 by 2/2. That would be 2x2 and 3 x2, which would be 4/6.

2/3 = 4/6
2/3 is equal to 4/6

Simplest Form
when finding simplest form, you are finding an equivalent fraction that has a numerator and denominator that cannot be reduced anymore.

To find simplest form you divide by a fraction equal to one.
The tricky part is finding a common factor of both the numerator and the denominator.


Put 15/20 in simplest form.
15 and 20 have a common factor of 5.
So divide 15/20 by 5/5. 15 divided by 5 is 3 and 20 divided by 5 is 4.

15/20 = 3/4
15/20 is equal to 3/4

3/4 is in simplest form because 3 is a prime number and because 3 and 4 have no common factors and cannot be divided further.

Finding a fraction of a number

Fraction of a number.

Alfredo has to read 24 pages in his science book by Friday. If he has completed 3/4 of the assignment, how many pages has he read?

We need to find 3/4 of 24. There are two ways to do that.

3/4 x 24/1
1. multiply 3/x 24 = 72 and 4 x 1 =4
2. that gives us 72/4 which is a division problem
3. 72 divided by 4 = 18
4. So 3/4 of 24 is 18.
5. So Alfredo has read 18 pages.

or

3/4 of 24
1. 24 divided by 4 = 6
2. 6 = 1/4 of 24
3. 1/4 + 1/4 + 1/4 = 3/4
4. 6 + 6 + 6 = 18
5. 3/4 of 24 is 18
6. So Alfredo has read 18 pages.