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Parts and Wholes - Introduction to Fractions

Grade 5CBSE

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

🔑Concepts

A fraction represents a part of a whole or a part of a collection. Imagine a whole circular chapati divided into 4 equal sectors; each sector represents the fraction 14\frac{1}{4} of the whole chapati.

The Numerator and Denominator define the fraction. The Denominator (bottom number) tells us how many equal parts the whole is divided into, while the Numerator (top number) tells us how many parts are being considered. For example, in a rectangle with 5 equal horizontal stripes where 2 are colored blue, the fraction of blue stripes is 25\frac{2}{5}.

Equivalent Fractions are different fractions that represent the same value or area. For instance, 12\frac{1}{2} of a square (cutting it down the middle) covers exactly the same amount of space as 24\frac{2}{4} of the same square (cutting it into four smaller squares and taking two).

Proper and Improper Fractions describe the size of the part relative to a single whole. A proper fraction like 38\frac{3}{8} is less than 1 whole because the numerator is smaller than the denominator. An improper fraction like 53\frac{5}{3} is greater than 1 whole and can be visualized as one full object plus 23\frac{2}{3} of another identical object.

Mixed Numbers combine a whole number and a proper fraction. For example, 2122 \frac{1}{2} represents two whole units and one-half of a third unit, often visualized as two full glasses of juice and one glass filled halfway.

Finding a fraction of a collection involves dividing the total group into equal parts. If you have 12 marbles and want to find 13\frac{1}{3}, you arrange them into 3 equal groups of 4; thus, 13\frac{1}{3} of 12 is 4.

Like and Unlike Fractions: Fractions with the same denominator are called 'Like Fractions' (e.g., 17\frac{1}{7} and 47\frac{4}{7}), which are easy to compare visually. Fractions with different denominators are called 'Unlike Fractions' (e.g., 12\frac{1}{2} and 13\frac{1}{3}).

📐Formulae

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

Value of a fraction of a quantity=Numerator×Total QuantityDenominator\text{Value of a fraction of a quantity} = \frac{\text{Numerator} \times \text{Total Quantity}}{\text{Denominator}}

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

Equivalent Fraction of ab=a×nb×n (where n0)\text{Equivalent Fraction of } \frac{a}{b} = \frac{a \times n}{b \times n} \text{ (where } n \neq 0)

💡Examples

Problem 1:

Rohan has a collection of 20 stamps. He gives 35\frac{3}{5} of his stamps to his sister. How many stamps does he give away?

Solution:

Step 1: Find the value of 15\frac{1}{5} of the stamps by dividing the total by the denominator: 20÷5=420 \div 5 = 4. Step 2: Multiply this value by the numerator to find 35\frac{3}{5}: 4×3=124 \times 3 = 12. Therefore, Rohan gives away 12 stamps.

Explanation:

To find a fraction of a total number, we divide the total into equal groups (denominator) and then count how many of those groups we need (numerator).

Problem 2:

Convert the mixed number 5235 \frac{2}{3} into an improper fraction.

Solution:

Step 1: Multiply the whole number by the denominator: 5×3=155 \times 3 = 15. Step 2: Add the numerator to the product: 15+2=1715 + 2 = 17. Step 3: Place the result over the original denominator: 173\frac{17}{3}.

Explanation:

This formula converts a combination of wholes and parts into a single fraction representing the total number of parts (thirds in this case).