Who needs LCM ?

First, three views of LCM with no comments :

### 1: Change them to equivalent fractions that will have equal

denominators. As the common denominator, choose the LCM of

the original denominators. Then the larger the numerator, the

larger the fraction.

### 2: Jun 26, 2011 – If b and d were same it was easy to find LCM

since if denominators are same, we just need to find LCM of

numerators, hence LCM of (a/b) and (c/b) would be LCM(a,c)/b.

So we have to first make denominators of both the fractions same.

Multiply numerator and denominator of first fraction by LCM

(b,d)/b.

### 3: The GCF and LCM are the underlying concepts for finding

equivalent fractions and adding and subtracting fractions, which

students will do later.

Now we can do fraction addition without LCM. It just needs the use of the distributive law, and the result shows the way in which the divisors combine.

And now using 3/4

But the best one is via multiplication ……

Now for multiplication and division.