130 likes | 531 Views
Dividing Fractions by Fractions. Academic Lab Math Intervention Lesson 3 of Dividing Fractions by Fractions. Let’s watch two video clips explaining what it means to divide fractions by fractions. http://www.teachertube.com/viewVideo.php?video_id=81294
E N D
Dividing Fractions by Fractions Academic Lab Math Intervention Lesson 3 of Dividing Fractions by Fractions
Let’s watch two video clips explaining what it means to divide fractions by fractions. • http://www.teachertube.com/viewVideo.php?video_id=81294 This video is 2:50 minutesabout multiplying the reciprocal in a song. • http://www.bing.com/videos/search?q=dividing+mixed+numbers+by+mixed+numbers&FORM=VIRE8&adlt=strict#view=detail&mid=6C123DE17967CD8774BB6C123DE17967CD8774BB This video is 9:50 minutes about how to divide mixed numbers by mixed numbers.
What is the difference between a MIXED NUMBER and its IMPROPER FRACTION? It’s all about how you represent the amount! The amount is either represented in “Wholes and Fractions” called Mixed Numbers. Get it? It’s a MIX of Wholes and Fractions! Or the same amount is ALL cut into EQUAL size fractionscalled Improper Fractions. The Wholes are CUT into fractions to EQUAL the fractional parts! That’s not “improper” at all!
What does it MEAN to CHANGE a MIXED NUMBER INTO AN IMPROPER FRACTION? What is a MIXED NUMBER? It’s a combo of Wholes AND Fractions! • If you had pizzasit would MEAN that you have 3 WHOLE pizzas and FRACTION of another pizza. It would LOOK like this… How do you CHANGE a MIXED NUMBER into an IMPROPER FRACTION? You CUT both the WHOLE and FRACTIONS into the SAME SIZE fractions! • Since the fraction of the pizza are cut into then we need to cut ALL of the pizza into or “thirds.” It would LOOK like this… There are now ELEVEN same size fractions which is the same asthe improper fraction of .
How can I use the standard algorithm to change mixed numbers into improper fractions?
How to use a Model when multiplying mixed numbers by mixed numbers Tessa has 7 cups of flour. She needs 1 cups of flour to make one loaf of bread. How many loaves she can make? • Start with representing the amount Tessa HAS! • Then divide it into groups of the amount she NEEDS per loaf. • How many loaves can Tessa make? 5 loaves!
How do you Solve division of Mixed Numbers using the standard algorithm of “Multiply the Reciprocal.” Start with what you HAVE then divide it by the size you NEED! STOP!!! You must change the Mixed Numbers into Improper Fractions. Cut all the wholes and parts into the same size fractions. See the model… Loaves Now you can “multiply the reciprocal” There are now 15 Equal HALVES! You need 3 Halves per loaf!
Student Practice! Susan has cups of chocolate chips in the cupboard. She is reading a recipe that needs cups for a batch of chocolate chip cookies. How many batches will Susan be able to make?
Review your work! Review your work! Review your work!Check each step! Did you solve it correctly? Susan has cups of chocolate chips in the cupboard. She is reading a recipe that needs cups for a batch of chocolate chip cookies. How many batches will Susan be able to make?
Congrats YOU have completed Lesson #3 of dividing fractions by fractions!You will be taking a Benchmark test the next time we meet to prove you understand how to divide fractions by fractions!