How do you work out least common denominator?

Answer 1

The least common denominator, or LCD, is the smallest positive integer that all the members of a given set of denominators will divide into evenly with no remainder.

also

The least common denominator in fractions is the lowest "bottom" number to which all the

fractions in the equation can equal for the purposes of addition and subtraction. When adding fractions, you must ensure that all fractions have the same denominator. Although it's okay to add numerators, you cannot add denominators. For example, 1/5 + 3/5 = 4/5, not 4/10.

So, what do you do if you have to calculate, say, 1/2 + 1/3? Since the denominators are different, you can't simply add them up. You must find the least common denominator (LCD) and find the equivalent fractions for each of the two original fractions using the LCD in their denominators.

One way of finding a common denominator -- albeit not necessarily the least (smallest) one -- is to multiply the two denominators. In the example above, 2 x 3 = 6. Six, therefore, could be substituted for the denominators of both fractions, and in this case it happens to be the LCD.

But how DO you add 1/2 + 1/3? We established 6 as the new denominator, so what fraction with 6 in the denominator is equal to 1/2? Well, 3/6 is equal to 1/2. And what fraction with 6 in the denominator is equal to 1/3? That would be 2/6.

So, now we have 3/6 + 2/6 = 5/6.

The Least Common Denominator (or LCD) is the Least Common Multiple (LCM) of the denominators of a pair of fractions.

The lowest multiple the denominators have in common.

Answer 2

You make a list of the multiples of both denominators and find the smallest one they both have. Then multiply the numerator by the same number to get the least common denominator. Example: 1/2 and 1/3. 0,2,4,6,8,10,12,14,16 and 0,3,6,9,12,15,18,21.

2x6=12, use the six. 1x6=6. 3x4=12, use the 4. 1x4=4. 1/2 and 1/3 =6/12 and 4/12. Takes practice.

Answer 3

That refers to the least number (or algebraic expression, in more general cases) that is a multiple of all the denominators you are considering. For example, if you want to add 1/2 + 1/3, you have to convert to a common denominator, so you convert both to sixths, since the number 6 is a multiple of both 2 and 3. (In this case, any common denominator would work, it need not be the smallest.)

Answer 4

Find the LCM of the denominators. Since the LCM of 3 and 4 is 12, the least common denominator of 1/3 and 1/4 is 12.

Answer 5

None, really. The process is the same. To find the least common denominator between 3/5 and 4/7, find the LCM of 5 and 7.

Answer 6

The least common denominator is the smallest positive integer that all the members of a given set of denominators will divide into evenly with no remainder.

Answer 7

Generally, a relationship consists of more than one thing.

Answer 8

The least common denominator, or LCD, is the smallest positive integer that all the members of a given set of denominators will divide into evenly with no remainder.

Answer 9

The LCD of a set of integers is the smallest positive integer which can be divided evenly by each integer in the set.

Answer 10

The least common denominator, for a set of rational fractions, is the lowest common multiple of the denominators.