Review the key concepts, formulae, and examples before starting your quiz.
πConcepts
Equivalent fractions are fractions that represent the same value or part of a whole, even though they have different numerators and denominators. For example, if you divide a rectangular bar into 2 equal parts and shade 1, or divide it into 4 equal parts and shade 2, the shaded area remains the same: .
To create an equivalent fraction, you can multiply both the numerator and the denominator by the same non-zero number. Visually, this is like taking an existing diagram and drawing more lines to create smaller sub-sections without changing the total colored portion.
Equivalent fractions can also be found by dividing both the numerator and the denominator by a common factor. This process is known as 'simplification' or 'reducing the fraction'. For instance, if you have of a circle shaded, you can group the 4 parts together to see it is equivalent to .
A fraction is in its simplest form (lowest terms) when the numerator and the denominator have no common factors other than 1. On a diagram, the simplest form uses the largest possible equal pieces to represent the portion.
On a number line, all equivalent fractions are represented by the same point. If you mark , , and on a number line between 0 and 1, all three marks will land on the exact same spot.
The Cross-Multiplication Method is a quick way to check for equivalence. If you have two fractions and , they are equivalent if the product of the first numerator and second denominator () equals the product of the first denominator and second numerator ().
When generating a series of equivalent fractions, you are essentially multiplying the original fraction by (which is equal to 1). Since multiplying any number by 1 does not change its value, the fractions remain equivalent: .
πFormulae
(where )
(where is a common factor of and )
π‘Examples
Problem 1:
Find an equivalent fraction of with denominator 35.
Solution:
Step 1: Determine what number the original denominator must be multiplied by to get the new denominator: . \ Step 2: Multiply the numerator by the same number: . \ Step 3: Write the new fraction: .
Explanation:
To maintain equivalence, we must multiply the numerator and denominator by the same number. Since the denominator increased by a factor of 5, the numerator must also increase by a factor of 5.
Problem 2:
Are the fractions and equivalent? Use cross-multiplication to check.
Solution:
Step 1: Multiply the numerator of the first fraction by the denominator of the second: . \ Step 2: Multiply the denominator of the first fraction by the numerator of the second: . \ Step 3: Compare the products. Since , the fractions are equivalent.
Explanation:
If the cross-products are equal, the two fractions represent the same ratio and are therefore equivalent.