Least Common Denominator is the least common multiple of two or more of fractions.
It is also called as Lowest Common Denominator.
Steps to find the Least Common Denominator:
1. First find the multiples of the denominators.
2. Identify the least common multiple.
To find the least common denominator of the fractions 4/7and 1/3, first we need to find the multiples of the denominator 7 i.e. 7, 14, 21, 28, 35 . . . and the multiples of the denominator 3 i.e. 3, 6, 9, 12, 15, 18, 21, 24 . . .
The least common multiple of the denominators 7 and 3 is 21.
So, the least common denominator of the fractionsand 4/7 and 1/3 is 21.
A. 12
B. 16
C. 4
D. 21
Correct Answer: A
Step 1: The denominators of the given fractions are 4 and 12.
Step 2: Multiples of 4 are 4, 8, 12, 16, 20 . . .
Step 3: Multiples of 12 are 12, 24, 36, 48 . . .
Step 4: The lowest multiple the numbers have in common is 12.
Step 5: So, the least common denominator of the given fractions is 12.
Q1: What is the LCD of 1/2 and 1/3?
Q2: What is the LCD of 5/4 + 7/12
Q: What is the difference between LCM and LCD?
A: The Least Common Multiple (LCM) is the smallest multiple that two or more numbers have in common. The Least Common Denominator (LCD) is the LCM of the denominators of two or more fractions.
Q: Why do we need to find the LCD?
A: Finding the LCD allows us to easily add or subtract fractions with different denominators.