Review the key concepts, formulae, and examples before starting your quiz.
๐Concepts
A fraction represents a part of a whole or a collection. For example, if a circular pizza is cut into 4 equal slices, each slice is represented as of the whole pizza.
In any fraction , the top number '' is called the Numerator (the number of parts we have) and the bottom number '' is the Denominator (the total number of equal parts the whole is divided into). Visually, if a rectangle is divided into 5 equal strips and 3 are shaded, the fraction is .
Equivalent Fractions are different fractions that name the same amount or part of a whole. Imagine two identical chocolate bars: one divided into 2 equal halves (where you eat 1) and another divided into 4 equal quarters (where you eat 2). In both cases, you have eaten the same amount because .
To find an equivalent fraction, multiply both the numerator and the denominator by the same non-zero number. For example, becomes if you multiply both parts by 2. This is like taking a shaded area and cutting all existing parts into smaller equal pieces.
Equivalent fractions can also be found by dividing both the numerator and the denominator by their common factor. For instance, the fraction can be simplified to by dividing both the top and bottom by 10.
You can test if two fractions and are equivalent using cross-multiplication. If the product of is equal to the product of , the fractions are equivalent.
A fraction is in its simplest form when the only common factor between the numerator and denominator is 1. For example, is in simplest form, whereas is not because both 6 and 8 can be divided by 2.
๐Formulae
(where )
(where is a common factor)
๐กExamples
Problem 1:
Find an equivalent fraction of that has a denominator of 20.
Solution:
Step 1: Determine what number the current denominator 5 must be multiplied by to get 20. Step 2: Multiply both the numerator and the denominator of by this number (4). Therefore, is the equivalent fraction.
Explanation:
To keep a fraction equivalent, any operation performed on the denominator must also be performed on the numerator. Since the denominator was scaled up by 4, we scale the numerator by 4 as well.
Problem 2:
Check whether and are equivalent fractions.
Solution:
Step 1: Use the cross-multiplication method. Multiply the numerator of the first fraction by the denominator of the second fraction: Step 2: Multiply the denominator of the first fraction by the numerator of the second fraction: Step 3: Compare the two results. Since , the fractions are equivalent.
Explanation:
If the cross-products of two fractions are equal, it confirms that the ratio between the parts and the whole is identical for both fractions.