Math Aid Lesson 1: Getting the Equivalent Value of Fractions

Elementary Math:
APGM’s Lesson 1

How to Find the Equivalent Value of a Fraction

1/5 of 45 is _____  answer: 9

Easy Solution/Technique:

Use the denominator to skip count until you reach the given whole number.  Since the denominator tells us how many parts a whole has been divided.

To illustrate:


5,    10  ,   15  ,  20 ,  25 ,   30  ,    35 ,  40  ,  45

 We based our skip-counting on 5 being our denominator and ended on 45 being the given whole number from where we are extracting the fraction’s equivalent. Count the sets of 5 till it reached 45 and you will find out it is 9. 5 being the first set and 45 the last set is 9th.

Actually, we don’t need a scratch paper here if the value is that small.  Just use your fingers. You will get the answer right away. Start on 5 and end on 45, it will show 9.

Another method is:

1/5 x 45/1 = 9
“of” is substituted by “x” operation symbol for multiplication. 
(1 x 45 = 45, will be our numerator) ((5 x 1 = 5 our denominators product)

therefore,

45/5 = 9

45 divided by 5 = 9

Another Example:

1/9 of 72  = ______ the answer is 8

How?
9 being the denominator – the base of our skip-counting. 72 the given whole number the ending point.

9   18   27  36   45   54  63   72

Counting the sets of nine, it shows 8

Another method

-1/9 x 72/1 = 72/9
-(1 x 72) = numerator (9x1) = denominator
 72/9  = 8

(72 divided by 9)

Divide 72 by 9 you will arrive on that same answer, 8.

If the numerator is a number other than 1, just multiply the answer to that given numerator since 1/9 of 72 is 8 that just mean that one part of 72 is 8 therefore to get 2 parts , we need to multiply that 1 part to 2.

e.g.
2/9 of 72
 1/9 of 72 is 8 x 2 = 16 

or

Another technique is:

2/9 x 72/1 = 144/9 = 16
-(2 x 72) numerator then (9x 1) = denominator
-144/9 (144 divided by 9)
-16


I have taught this to my eldest, Angel Reign and that part of their Math exam with questions like these, she got it 100% correct, that is in her grade 1 maybe that proves this is easier for children. Hope to have helped you teach these methods to your children too.  

Thanks for reading

.
Post a Comment

Google+ Followers

Creative Commons License

Creative Commons License
Family, Daily Living & Style by Angelita Galiza-Madera is licensed under a Creative Commons Attribution 4.0 International License.