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Category Archives: Fractions

Factions easy as 1,2,3!

It is important to have a sence about the size of fractions to be able to estimate what the answer is.

For example we can say that 3/5 + 1/2 is approximately equal to 1 or just over one. We can say this because 3/5 is just over a half. Therefore if we add what they are close to we can see that it will be just over 1.

Not only can we make an estimation of what the answer might be but we can use the rectangle method of multiplication for fractions!

Not only can we use this method with whole number but we can use this for fractions. The picture below shows a few examples of using this method with fractions.

When using the Rectangle Method of Multiplication for fractions you have to be able to think in parts of a whole. For example when we do 1/2 x 2/3 (the bottom problem in the picture above) we start with a 1×1 square, then we have to split the square into halves in one direction, and then into thirds in the other direction. After we do this we can shade in 2/3. By splitting the 1×1 square into half in one direction and thirds in the other we get a box that is sixths, this gives us a final answer of 2/6 because there are six parts and two of them are shaded.

We can also use this method for division of fractions if you change the division into multiplication. Here are some videos that can help explain adding and subtraction of fractions. It will also help explain multiplication and division.


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Posted by on October 28, 2011 in Fractions

 

Apples, Oranges, and Grapes

Fractions are part of our every day life; we use them all the time without even knowing it. A Fraction is simply when an object or a number is divide into equal parts; each part is a fraction of the whole. There are aways to parts to a fraction. The first part is the Numerator or the “number on the top”. The Numerator is the number of the shaded parts of the whole. The second part is the Denominator or the “number on the bottom”. We can think of the Denominator as units, or all the parts. The Denominator can also never be zero.

The Picture to the left is a Fraction Bar, we can use this to show a fraction with shading and to help us solve problems. This fraction happens to be fourths. Three out of the four squares are shaded therefore it is 3 fourths. This can also be written as a fraction.

To write this as a fraction you would put the 3 in the Numerator, because this is the shaded part of the whole, and you would put the 4 in the denominator because this is the whole number or the units.

This is another Fraction bar, however the size and the shading has changed. This fraction bar represents halves.1 out of two have halves are shaded therefore it is 1 half.

To write this as a fraction you would put the 1 in the numerator, the shaded part. and a 2 in the denominator because there are 2 parts or units.

Another way to use Fraction Bars are to find equivalent fractions. We can take a fraction like 2/3 and find all the fractions that are equal to it.

In the picture above we can see that 2/3 is equal to 4/6 and 8/12.

Another way that we can tell if fractions are equal is by taking the original fraction, and multiplying it by 2/2, 3/3, 4/4 and so on.

2/4 = 4/8 = 3/12 = 8/16

This is a much easier way to understand and work with fractions.

 
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Posted by on October 20, 2011 in Fractions