In adding and subtracting fractions with unlike denominators, you have to get a least common denominator which is exactly like the least common multiple it just so happens to be in the denominator.

Have you ever tried to add or subtract fractions that have different denominators? It’s tricky, right? Join Ms. Susanna Post in this lesson to learn how to solve these types of challenging ...

Even if students get the basic concepts right—that fractions don’t behave the same way that whole numbers do—the rules of how to operate on fractions can stump learners.