Subtracting Fractions By, Mrs. Muller

What does it mean to subtract Fractions? It is when we take away a part of a whole from another part of a whole. For example: You have 5 out of 6 slices of pie in the fridge. Your brother and you each have one slice of pie (2 out of 6 slices total). How much pie do you have left? What do you notice about subtracting fractions?

The Procedure The denominators must be the same Subtract the numerators from each other. Keep the denominators the same.

Let’s Practice

What do we do when the denominator is different? Let’s say we have the problem ½-1/3= Let’s use the fraction strips to come up with a rule. What fraction strips can be used to make the ½ and the 1/3? What do you notice about subtracting fractions with different denominators?

The Procedure for subtracting fractions with different denominators. ½-1/3= First find the least common multiple of the denominators. Second multiply the numerator by what it took to get the LCM and make the denominator the LCM Third use the new fractions to add them together now that the denominators are the same. 2x1 2x2 2x3 3x1 3x2

Let’s Practice

Compare and Contrast Adding and Subtracting Fractions Use a double bubble map to compare and contrast Adding and Subtracting Fractions.