Bobby's Last Fraction Post

Thursday, May 7, 2009
Okay, so uhm. fractions are over, YES!!
So, now here's my last post about fractions.

How to subtract fractions

Subtracting fractions is easy.
Here's the first question :

6/12 - 3/4=

First we need to find what 12 and 4 goes into. We could multiply each other, and we get 48. We could use 48 but just 12 is more easier. We multiply 12 by 1 and 4 by 3. Those both equals to twelve. Then whatever we used to multiply the denominator we multiply it with the numerator. So, we multiply 6 by 1 and 3 by 3. Now, it's like this : 6/12 - 9/12=
Now, we solve it: 15/12. Here we have an improper fractions, we could make this into a mixed number by dividing 15 with 12. so it's: 1 3/12.
Here is a picture of it:

How to Add fractions

I'm going to explain three questions.

Number one is:

2/3 + 1/8

What you do here is you find the quotient of 3 x 8.

Then whatever my answer that becomes my denominator.

In this case, it's 24. So, your denominator will be 24. /24 + /24.
Now, it's time to look for the numerator. I will multiply the number 8 by 2 because 2 is the number I multiplied it with the number eight to get the 24 I wanted for the denominator.
I will do the same thing on the other side but different numbers because i used a different number to multiply it by 8 to get 24. So, the number is 3, then I would multiply it by 1 and the
quotient is 3.
All this becomes like this:
16/24 + 3/24
Since both denominators are the same, all I need to add is the numerator.
The answer is 19/24.

Here is a picture of the question.

The next question will be a mixed number, it will explain and show how to add mixed numbers.

1 2/3 + 1 1/4=

If it's a mixed number then just add the whole number. So, here it's 2__.
Then we just solve the fractions, so it looks like this: 2/3 + 1/4=
We multiply both denominators and we get 12. Now, the denominator is 12. We multiply 2 by 4 and 1 by 3, the answer now is 8/12 + 3/12=.
We get 11/12. We put the 2, 2 11/12.
Here is a bad picture of it :)

Multiplying Fractions

Fraction is very easy, you just multiply
both numbers in the numerator and multiply the numbers in the denominators.
So here, it's 4 multiply by 1 equals 4. Then 6 multiply by 2 equals 12. So, it's 4/12. We could simply it down to 1/3.

Multiplying mixed numbers

2 2/6 x 1/12

If we have a mixed number in our questions all we have to do is make it a improper fractions. To do that, we multiply our whole number to the denominator then add the numerator. Then we just solve, 14 by 1 and 6 by 12. The fraction comes as an improper then we just divide it. Then we get 2 1/4.

How to divide fractions

To divide we just have to do the reciprocal.

It shows clearly on the picture.


To divide mixed fractions we just make the mixed fractions to an improper fractions. Then we do the reciprocal.
If the numerator is larger than the denominator, we just divide the 9 into 20

Problem 1

15 scoops make ___ cake.
15 scoops make 6 2/3 cake.

Problem 2

It was sunny for ___ hours that day.

It was sunny for 3 1/2 hours that day.

Finally, I'm done.


Post a Comment