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Fractions - Fraction on the Number Line

Grade 6CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

A number line is a horizontal line where numbers are marked at equal intervals. To represent fractions, we divide the unit length (the distance between 00 and 11, 11 and 22, etc.) into equal parts based on the denominator. Visual: Imagine a straight line starting at 00 on the left, with points marked with ticks to show equal spacing.

Proper fractions, where the numerator is less than the denominator (n<dn < d), always lie between 00 and 11 on the number line. Visual: If you are plotting 12\frac{1}{2}, the point will be exactly in the middle of the segment starting at 00 and ending at 11.

The denominator of a fraction tells us the total number of equal divisions we must make in each unit length. For example, if the denominator is 44, the space between 00 and 11 must be divided into 44 equal segments using 33 marks between them.

The numerator tells us how many parts to count from the zero mark. To plot 35\frac{3}{5}, you would divide the space between 00 and 11 into 55 equal parts and then count 33 marks to the right of 00.

On any number line divided into nn equal parts between 00 and 11, the point 00 can be written as 0n\frac{0}{n} and the point 11 can be written as nn\frac{n}{n}. Visual: On a line divided into 77 parts, the point 11 sits exactly at the 7th7^{th} mark, which represents 77\frac{7}{7}.

Improper fractions, where the numerator is greater than the denominator (n>dn > d), represent values greater than 11. To plot these, the number line must extend beyond 11. Visual: To plot 54\frac{5}{4}, you continue the sequence of equal divisions past 11 to the next mark, which represents 1141 \frac{1}{4} or 54\frac{5}{4}.

Mixed fractions are plotted by first identifying the whole number part and then the fractional part. For 2132 \frac{1}{3}, you move to the whole number 22 and then move 13\frac{1}{3} of the way toward the next whole number 33. Visual: This point will be located between the marks for 22 and 33, specifically at the first of three equal divisions.

📐Formulae

Fraction=NumeratorDenominator\text{Fraction} = \frac{\text{Numerator}}{\text{Denominator}}

Position of mark k between 0 and 1=kn\text{Position of mark } k \text{ between } 0 \text{ and } 1 = \frac{k}{n}, where nn is the total number of divisions.

1=nn1 = \frac{n}{n} (where n0n \neq 0)

0=0n0 = \frac{0}{n} (where n0n \neq 0)

Improper Fraction=(Whole Number×Denominator)+NumeratorDenominator\text{Improper Fraction} = \frac{(\text{Whole Number} \times \text{Denominator}) + \text{Numerator}}{\text{Denominator}}

💡Examples

Problem 1:

Represent 35\frac{3}{5} on the number line.

Solution:

Step 1: Identify that 35\frac{3}{5} is a proper fraction, so it lies between 00 and 11. Step 2: Draw a straight line and mark points 00 and 11. Step 3: Since the denominator is 55, divide the segment between 00 and 11 into 55 equal parts. This requires making 44 equidistant marks between 00 and 11. Step 4: Label the marks as 15,25,35,\frac{1}{5}, \frac{2}{5}, \frac{3}{5}, and 45\frac{4}{5} starting from the left. Step 5: Identify the third mark from 00, which represents 35\frac{3}{5}.

Explanation:

We divide the unit length into 5 equal parts because the denominator is 5, and we take 3 of those parts because the numerator is 3.

Problem 2:

Represent 83\frac{8}{3} on the number line.

Solution:

Step 1: Convert the improper fraction 83\frac{8}{3} to a mixed fraction: 8÷3=28 \div 3 = 2 with a remainder of 22. So, 83=223\frac{8}{3} = 2 \frac{2}{3}. Step 2: This value lies between the whole numbers 22 and 33. Step 3: Draw a number line and mark 0,1,2,0, 1, 2, and 33. Step 4: Divide the segment between 22 and 33 into 33 equal parts (since the denominator is 33). Step 5: Starting from the point 22, count 22 divisions to the right. Step 6: Mark this point as 2232 \frac{2}{3} or 83\frac{8}{3}.

Explanation:

By converting to a mixed fraction, we easily see that the point is 2 full units plus 2/3 of the next unit.