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

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 problems!

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.

Click here to see a step-by-step slideshow. STEP 1 - Draw a square with 5 columns (5 is the denominator of the first fraction) and a square with 4 rows (4 is the denominator of the second fraction).