Equivalent Rational Numbers

We will learn how to find the equivalent rational numbers by multiplication and division.


Equivalent rational numbers by multiplication:

If ab  is a rational number and m is a non-zero integer then a×mb×m is a rational number equivalent to ab

For example, rational numbers 1215202528354860 are equivalent to the rational number 45.

We know that if we multiply the numerator and denominator of a fraction by the same positive integer, the value of the fraction does not change.

For example, the fractions 37 and 2149 are equal because the numerator and the denominator of 2149 can be obtained by multiplying each of the numerator and denominator of 37 by 7.  

Also, 34 = 3×(1)4×(1) = 34, 34 = 3×24×2 = 68, 34 = 3×(2)4×(2) = 68 and so on …….

Therefore, 34 = 3×(1)4×(1) = 3×24×2 = (3)×(2)4×(2) and so on …….

Note: If the denominator of a rational number is a negative integer, then by using the above property, we can make it positive by multiplying its numerator and denominator by -1.

For example, 57 = 5×(1)(7)×(1) = 57


Equivalent rational numbers by division:

If ab is a rational number and m is a common divisor of a and b, then a÷mb÷m is a rational number equivalent to ab.

For example, rational numbers 4860, 2835, 2025, 1215 are equivalent to the rational number 45.

We know that if we divide the numerator and denominator of a fraction by a common divisor, then the value of the fraction does not change.

For example, 4864 = 48÷1664÷16 = 34

Similarly, we have
75100 = (75)÷5100÷5 = 1520 = (15)÷520÷5 = 34, and
4256 = 42÷2(56)÷2 = 2128  = 21÷(7)(28)÷(7) = 34


Solved examples:

1. Find the two rational numbers equivalent to 37.

Solution:

37 = 3×47×4 = 1228 and

37 = 3×117×11 = 3377

Therefore, the two rational numbers equivalent to 37 are 1228 and 3377


2. Determine the smallest equivalent rational number of 210462.

Solution:

210462 = 210÷2462÷2 = 105231 = 105÷3231÷3 = 3577 = 35÷777÷7 = 511

Therefore, the least equivalent rational number of 210462 is 511


3. Write each of the following rational numbers with positive denominator:

                  371128, 1913

Solution:

In order to express a rational number with positive denominator, we multiply its numerator and denominator by -1.

Therefore,

37 = 3×(1)(7)×(1)37,

1128 = 11×(1)(28)×(1)1128,

and 1913 = (19)×(1)(13)×(1)1913


4. Express 37 as a rational number with numerator:

(i) -15;                 (ii) 21

Solution:  

(i) In order to -3 as a rational number with  numerator -15, we first find a number  which when multiplied by -3 gives -15.

Clearly, such number is (-15) ÷ (-3) = 5
Multiplying the numerator and denominator of 37 by 5, we have

37(3)×57×5 = 1535

Thus, the required rational number is 1535.


(ii) In order to express 37 as a rational number with numerator 21, we first find a number which when multiplied with -3 gives 21. 

Clearly, such a number is 21 ÷ (-3) = -7 

Multiplying the numerator and denominator of 37 by (-7), we have

37 = (3)×(7)7×(7) = 2149


These are the above examples on equivalent rational numbers.

Rational Numbers

Introduction of Rational Numbers

What is Rational Numbers?

Is Every Rational Number a Natural Number?

Is Zero a Rational Number?

Is Every Rational Number an Integer?

Is Every Rational Number a Fraction?

Positive Rational Number

Negative Rational Number

Equivalent Rational Numbers

Equivalent form of Rational Numbers

Rational Number in Different Forms

Properties of Rational Numbers

Lowest form of a Rational Number

Standard form of a Rational Number

Equality of Rational Numbers using Standard Form

Equality of Rational Numbers with Common Denominator

Equality of Rational Numbers using Cross Multiplication

Comparison of Rational Numbers

Rational Numbers in Ascending Order

Rational Numbers in Descending Order

Representation of Rational Numbers on the Number Line

Rational Numbers on the Number Line

Addition of Rational Number with Same Denominator

Addition of Rational Number with Different Denominator

Addition of Rational Numbers

Properties of Addition of Rational Numbers

Subtraction of Rational Number with Same Denominator

Subtraction of Rational Number with Different Denominator

Subtraction of Rational Numbers

Properties of Subtraction of Rational Numbers

Rational Expressions Involving Addition and Subtraction

Simplify Rational Expressions Involving the Sum or Difference

Multiplication of Rational Numbers

Product of Rational Numbers

Properties of Multiplication of Rational Numbers

Rational Expressions Involving Addition, Subtraction and Multiplication

Reciprocal of a Rational  Number

Division of Rational Numbers

Rational Expressions Involving Division

Properties of Division of Rational Numbers

Rational Numbers between Two Rational Numbers

To Find Rational Numbers






8th Grade Math Practice 

From Equivalent Rational Numbers to HOME PAGE




Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.



New! Comments

Have your say about what you just read! Leave me a comment in the box below. Ask a Question or Answer a Question.




Share this page: What’s this?

Recent Articles

  1. Quadrilaterals | Four Sided Polygon | Closed Figure | Adjoining Figure

    Jul 14, 25 02:55 AM

    Square
    Quadrilaterals are known as four sided polygon.What is a quadrilateral? A closed figure made of our line segments is called a quadrilateral. For example:

    Read More

  2. Formation of Numbers | Smallest and Greatest Number| Number Formation

    Jul 14, 25 01:53 AM

    In formation of numbers we will learn the numbers having different numbers of digits. We know that: (i) Greatest number of one digit = 9,

    Read More

  3. 5th Grade Geometry Practice Test | Angle | Triangle | Circle |Free Ans

    Jul 14, 25 01:53 AM

    Name the Angles
    In 5th grade geometry practice test you will get different types of practice questions on lines, types of angle, triangles, properties of triangles, classification of triangles, construction of triang…

    Read More

  4. 5th Grade Circle Worksheet | Free Worksheet with Answer |Practice Math

    Jul 11, 25 02:14 PM

    Radii of the circRadii, Chords, Diameters, Semi-circles
    In 5th Grade Circle Worksheet you will get different types of questions on parts of a circle, relation between radius and diameter, interior of a circle, exterior of a circle and construction of circl…

    Read More

  5. Construction of a Circle | Working Rules | Step-by-step Explanation |

    Jul 09, 25 01:29 AM

    Parts of a Circle
    Construction of a Circle when the length of its Radius is given. Working Rules | Step I: Open the compass such that its pointer be put on initial point (i.e. O) of ruler / scale and the pencil-end be…

    Read More

Rational Numbers - Worksheets

Worksheet on Rational Numbers

Worksheet on Equivalent Rational Numbers

Worksheet on Lowest form of a Rational Number

Worksheet on Standard form of a Rational Number

Worksheet on Equality of Rational Numbers

Worksheet on Comparison of Rational Numbers

Worksheet on Representation of Rational Number on a Number Line

Worksheet on Adding Rational Numbers

Worksheet on Properties of Addition of Rational Numbers

Worksheet on Subtracting Rational Numbers

Worksheet on Addition and Subtraction of Rational Number

Worksheet on Rational Expressions Involving Sum and Difference

Worksheet on Multiplication of Rational Number

Worksheet on Properties of Multiplication of Rational Numbers

Worksheet on Division of Rational Numbers

Worksheet on Properties of Division of Rational Numbers

Worksheet on Finding Rational Numbers between Two Rational Numbers

Worksheet on Word Problems on Rational Numbers

Worksheet on Operations on Rational Expressions

Objective Questions on Rational Numbers