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Fractions - A Pinch of History

Grade 6CBSE

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

🔑Concepts

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A fraction represents a part of a whole. In the form ab\frac{a}{b}, 'aa' is the numerator and 'bb' is the denominator.

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Ancient Egyptians primarily used 'Unit Fractions', which are fractions with a numerator of 11, such as 12\frac{1}{2}, 13\frac{1}{3}, or 110\frac{1}{10}.

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In ancient India, mathematicians like Brahmagupta wrote fractions as one number above another (e.g., 34\begin{smallmatrix} 3 \\ 4 \end{smallmatrix}) but without the horizontal bar (vinculum). The bar was later introduced by Arabs.

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A Proper Fraction is where the numerator is less than the denominator (a<ba < b), representing a value less than 11, like 35\frac{3}{5}.

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An Improper Fraction has a numerator greater than or equal to the denominator (a≥ba \ge b), like 74\frac{7}{4}.

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A Mixed Fraction consists of a whole number and a proper fraction, such as 2132 \frac{1}{3}.

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Equivalent Fractions are obtained by multiplying or dividing the numerator and the denominator by the same non-zero number. For example, 12=1×22×2=24\frac{1}{2} = \frac{1 \times 2}{2 \times 2} = \frac{2}{4}.

📐Formulae

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

Mixed Fraction=Whole Number+NumeratorDenominator\text{Mixed Fraction} = \text{Whole Number} + \frac{\text{Numerator}}{\text{Denominator}}

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

ab=a×nb×n (where n≠0)\frac{a}{b} = \frac{a \times n}{b \times n} \text{ (where } n \neq 0)

ab=a÷mb÷m (where m is a common factor)\frac{a}{b} = \frac{a \div m}{b \div m} \text{ (where } m \text{ is a common factor)}

💡Examples

Problem 1:

Convert the mixed fraction 3253 \frac{2}{5} into an improper fraction.

Solution:

325=(3×5)+25=15+25=1753 \frac{2}{5} = \frac{(3 \times 5) + 2}{5} = \frac{15 + 2}{5} = \frac{17}{5}

Explanation:

Multiply the whole number by the denominator, add the numerator, and keep the same denominator.

Problem 2:

Find an equivalent fraction of 47\frac{4}{7} with denominator 2828.

Solution:

To get a denominator of 2828, we multiply 77 by 44. So, 4×47×4=1628\frac{4 \times 4}{7 \times 4} = \frac{16}{28}

Explanation:

To maintain equivalence, we must multiply both the numerator and the denominator by the same number.

Problem 3:

Subtract the numerators of two like fractions 1520\frac{15}{20} and 720\frac{7}{20} using vertical alignment for the calculation.

Solution:

The denominator remains 2020. For the numerator: 15−78\begin{array}{r} 15 \\ - 7 \\ \hline 8 \end{array} Thus, the result is 820\frac{8}{20}, which simplifies to 25\frac{2}{5}.

Explanation:

When subtracting like fractions, we subtract the numerators and keep the common denominator.