Fractions can be added in different ways: When the denominators are the same, add the numerators. Sometimes the final answer can be simplified. close simplify (a fraction)To reduce a fraction to ...

Use visual fraction models to add and subtract fractions with the same denominators.

Another sticking point for many students is adding fractions with different denominators—for example, coming up with 11/12 when asked to add 3/5 and 8/7.

There's a helpful shortcut worth remembering: if your fractions already share the same denominator, you can skip straight to adding or subtracting the numerators. No LCD hunting required.

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 ...

But the same concept holds true. Common Denominator The common denominator model, while not really a picture, demonstrates that the same rules apply to multiplication and division with fractions.

Why do you need to find the lowest common denominator when adding or subtracting fractions but not when multiplying them? And why do you have to invert the second fraction and multiply when dividing?