Adding and Subtracting Like Fractions, Least Common Denominator, Section 4.4 Adding and Subtracting Like Fractions, Least Common Denominator, and Equivalent Fractions

Like Fractions Like Fractions are multiple fractions with the same (exact) denominator. Given the fractions below group the like fractions.

Adding Like Fraction If a, b, and c are numbers and b is not equal to zero

Subtracting Like Fraction If a, b, and c are numbers and b is not equal to zero

Lease Common Denominator Least Common Denominator (LCD) is the smallest positive number divisible by all the denominators in the list.

LCD Methods Multiples Prime Factorization

Finding LCD by Multiples Steps List the multiples of each denominator Find the same multiples in each list The smallest multiple is the LCD

Finding LCD by Multiples Find the LCD for LCD = 30

Example Find the LCD

Example Find the LCD

Finding LCD by Prime Factorization Steps Write each denominator in prime factorization. Compare like prime numbers Underline the group with the largest amount If the amounts are equal underline one group Multiply all underlined numbers together

Finding LCD by Prime Factorization Find the LCD for 6 = 2 * 3 10 = 2 * 5 LCD = 2 * 3 * 5 = 30

Example Find the LCD

Example Find the LCD

Equivalent Fractions Equivalent Fractions are two or more fractions that have the same value even if they look different.

Equivalent Fraction To write an equivalent fraction Where a, b, and c are nonzero numbers

Example Fill in the missing part to create an equivalent fraction

Example Fill in the missing part to create an equivalent fraction

Example Fill in the missing part to create an equivalent fraction

Example Fill in the missing part to create an equivalent fraction