7th Grade Math - Solve Proportions by using Equivalent Fractions

In this video, you will learn how to solve proportions by using equivalent fractions. Equivalent fractions are fractions that are equal to each other. Proportion is an equation that says two ratios are equivalent.

Solve Proportions by using Equivalent Fraction Method

Finding Equivalent Fractions and Decimals using Percents

Preview

Finding equivalent fractions and decimals using percents is a really long title but actually the topic is really easy.
So first let's find an equivalent fraction using a percent and to do that we need a percent so let's take 22% and now we have to make the percent into a fraction like this:

22% = 22 

           100

And now we have to make an equivalent fraction so we have to multiply both the numerator and denominator with the same number so multiply them by the number 5 ( or any other number )like this:

22% = 22   =  22  x 5= 110

           100     100 x 5= 500

So now we know that an equivalent fraction for the fraction 22/100 is 110/500.


Now let's find a decimal using a percent and to do that we have to take a percent so let's take the percent 45% and we have to make it into a fraction like this:

45% = 45  

           100

And now we have to make it into a decimal by dividing 45 by 100 like this:

45   = 0.45

100

So now you know that the decimal number for the fraction 45/100 is 0.45.
Now try some of these and make sure to watch the video on YouTube.

 

Sheet 1 How to Find Equivalent Fractions

Common Denominators

Preview

Common denominators can be very useful when you are doing addition and subtraction with fractions. So what are common denominators and how do you find them? Common denominators are two denominators of two fractions that are common. So let's take the two fractions 3/4 and 3/5 and to find the common denominators for the two fractions we will have to write the fractions out in vertical form like this:

3

4

    

5

6

So now that we have the two fractions we have to take the denominators and find the LCM of the two numbers like this:

3

4                            4, 8, 12, 16, 20

    =  4 and 6 =                                  LCM=12

5                            6, 12, 18, 24, 30

6

We know that the LCM of the two denominators is 12 so now we have to rename the fractions like this:

3     = ?            

4        12

5     = ?   

6        12

So now we have to rename the numerators by multiplying them by the same we multiplied each denominator by to get 12 like this:

3          9    

4         12

=4 x 3=12

5         10

6         12

=6 x 2=12

We now know that the common denominators for the two fractions 3/4 and 5/6 is 12. And so our fractions with common denominators are 9/12 and 10/12.
Now try some of these and make sure to watch the video on YouTube.

Sheet 1 How to find Common Denominators

Sheet 2 How to find Common Denominators

What are Equivalent Fractions

Introduction

Equivalent fractions are basically like multiples, except they involve fractions. What I mean is that, like, when you are finding multiples of numbers like let's say 3. We'll write them like this:

3,6,9,12...

Equivalent fractions are pretty much the same thing but you just have to have a numerator and a denominator and also you must multiply both the numerator and denominator by the same number.

Let's Do It!

Now that we know the basics about equivalent fractions, let's try it out.

Let's say that we have 2/3 and we have to find an equivalent fraction for this fraction. Remember to multiply both the numerator and denominator by the same number. Also keep in mind that the number can be any number. In this case, we'll multiply 2/3 by 4:

2x4=8

3x4=12

Therefore, our equivalent fraction for 2/3 equals 8/12.

Wasn't that easy?!

Sheet 1 Practice Problems on Equivalent Fractions