This document provides instruction on adding fractions with different denominators. It begins by explaining why understanding fractions is important for success in algebra and beyond. It then defines the key parts of a fraction and establishes the important rule that fractions can only be added if they have a common denominator. The document demonstrates how to find the lowest common denominator and convert fractions to equivalent forms with the common denominator in order to add them. It emphasizes that equivalent fractions allow fractions to retain their original value even when the denominator changes.

1. Norm FrankenbergerAdding Fractions+With Different DenominatorsAdding Fractions

2. Adding FractionsNorm FrankenbergerSummary SlideWhy Adding Fractions Is Important? Identifying the Parts of a FractionThe Most Important RuleWhat If the Fractions You’re Adding Have Different DenominatorsChoosing a Common DenominatorConverting Fractions to EquivalentsEquivalent Fractions

3. Why Adding Fractions Is Important?In March 2008, a presidential panel reported after a two year study that “schools could improve students’ math scores by hammering home the basics, such as addition and multiplication, and then increasing the focus on fractions and geometry.In addition the report stated…Adding FractionsNorm Frankenberger

4. Adding FractionsNorm Frankenberger“Difficulty with fractions (including decimals and percents) is pervasive and is a major obstacle to further progress in mathematics, including algebra.”Success in algebra is linked to higher graduation rates and college enrollment.Let’s get started!

5. Norm FrankenbergerIdentifying the Parts of a FractionThe top number is called the numerator.The bottom number is called the denominator.34 numeratordenominatorAdding Fractions

6. Norm FrankenbergerThe Most Important Rule You CANNOT add (or subtract) fractions unless the denominators are the same!13+ 14does not add up to 27Adding Fractions

7. Adding FractionsNorm FrankenbergerWhat If the Fractions You’re Adding Have Different DenominatorsYou must choose a new common denominator You must change the fractions into their equivalent forms.

8. Adding FractionsNorm FrankenbergerChoosing a Common Denominator1 + 314Go through the list of multiples of the two denominators and pick out the first number that appears in both lists.This is the common denominator!

9. Adding FractionsNorm FrankenbergerConverting Fractions to Equivalents Put equal signs and the common denominator next to the original fractions

10. Ask, “Three times what number equals twelve?”

11. Answer: “Four”

12. Now, whatever you do the bottom of the fraction, you must do to the top.

13. Multiply the numerator times fourx 4 = 12 121 + 314 4 ==x 4 =x 3 = 3 x 3 =Now repeat the same process with the second fraction.