Adding fractions is very easy. Before learning how to add fractions, we need to revise like & unlike fractions. We will quickly recall here that that a fraction has two parts, a numerator & a denominator. The fractions with same denominators are called like fractions; while the fractions with different denominators are called unlike fractions.
Now, when we have to add fractions, we must always remember that the fractions can be added or even subtracted; only when they are likewise., they have same denominators. If in any case, the denominators are different, we first make them same.
We can convert unlike fractions into like or in simple words, make the denominators of fractions same by finding the LCM of the denominators of the fractions to be added & then getting the equivalent fractions with such denominator, as is the LCM. Then, we continue addition of fractions by adding only the numerators of the addendent fractions. It is worth mentioning here that the denominators of the fractions are not added, rather it is written only once after being the LCM of denominators. It is always advisable to change the answer fraction to its mixed form; in case it is in improper fraction.
We will see some examples here.
To add 2/7 & 3/5 , we observe that the fractions are unlike. So, we will find the LCM of the denominators, 7 & 5 which is 35. Now, we will change the addendents to their equivalent forms with denominator 35 & we get, 2/7=(2*5)/(7*5)=10/35.
Also, 3/5=(3*7)/(5*7)=21/35
Now, adding these two fractions, we get 2/7+3/5=10/35+21/35 =(10+21)/35=31/35
In another example, 7/5+3/6+8/15. Here, the LCM of 5,6,15 is 30.
So, the fractions will be written as:
7/5=(7*6)/(5*6) =42/30
3/6=(3*5)/(6*5)=15/30
8/15=(8*2)/(15*2)=16/30
Adding these, we get 7/5+3/6+8/15 = (42+15+16)/30 = 73/30.
Since 73/30 is improper fraction, we’ll convert it to mixed fraction & the final sum of the given fractions is 2 13/30.
You can get Homework help & also class 8 cbse syllabus online and In the next session we will discuss about how to multiply fractions.
Now, when we have to add fractions, we must always remember that the fractions can be added or even subtracted; only when they are likewise., they have same denominators. If in any case, the denominators are different, we first make them same.
We can convert unlike fractions into like or in simple words, make the denominators of fractions same by finding the LCM of the denominators of the fractions to be added & then getting the equivalent fractions with such denominator, as is the LCM. Then, we continue addition of fractions by adding only the numerators of the addendent fractions. It is worth mentioning here that the denominators of the fractions are not added, rather it is written only once after being the LCM of denominators. It is always advisable to change the answer fraction to its mixed form; in case it is in improper fraction.
We will see some examples here.
To add 2/7 & 3/5 , we observe that the fractions are unlike. So, we will find the LCM of the denominators, 7 & 5 which is 35. Now, we will change the addendents to their equivalent forms with denominator 35 & we get, 2/7=(2*5)/(7*5)=10/35.
Also, 3/5=(3*7)/(5*7)=21/35
Now, adding these two fractions, we get 2/7+3/5=10/35+21/35 =(10+21)/35=31/35
In another example, 7/5+3/6+8/15. Here, the LCM of 5,6,15 is 30.
So, the fractions will be written as:
7/5=(7*6)/(5*6) =42/30
3/6=(3*5)/(6*5)=15/30
8/15=(8*2)/(15*2)=16/30
Adding these, we get 7/5+3/6+8/15 = (42+15+16)/30 = 73/30.
Since 73/30 is improper fraction, we’ll convert it to mixed fraction & the final sum of the given fractions is 2 13/30.
You can get Homework help & also class 8 cbse syllabus online and In the next session we will discuss about how to multiply fractions.
No comments:
Post a Comment