Dividing Fractions by Fractions Academic Lab Math Intervention Day 1 of Dividing Fractions by Fractions

Let’s watch two video clips explaining what it means to divide fractions by fractions. http://www.virtualnerd.com/middle-math/multiplying-dividing-fractions/divide/meaning-dividing-fractions This video is 6:40 minutes. http://www.khanacademy.org/video/conceptual-understanding-of-dividing-fractions-by-fractions This video is just over 5 minutes.

Remember to create full bars of the same size. Practice #1 A video game required a player to have 1 4 of a credit in order to play for a minute. Emma has 7 8 credit. How many minutes can Emma play? We want to know how many 1 4 credits (to play for minute) fit in 7 8 credit. Let’s draw a model. Remember to create full bars of the same size. 7/8 credits earned 1/4 credit per minute 1/8 1/8 (not earned) 1/4

We can ask… how many 1/4 are there in 7/8? 7 8 =?× 1 4 How many 1/8 fractions are in ONE 1/4 fraction? There are TWO 1/8 fractions in ONE 1/4 fraction. So if there are only SEVEN 1/8 fractions which is the same as 7/8. How many 1/4 fractions are there in 7/8? There are 3 1 2 (three and a half) 1/4 fractions in 7/8. If each 1/4 equals one minute of credit on the video game, how long will Emma get to play the video game? Emma can play the video game for 3 1 2 minutes with her credits.

“Stay, Change, Change!” Write it as a multiplication problem. Let’s solve this same problem using the standard algorithm of “Multiply the Reciprocal.” A video game required a player to have 1 4 of a credit in order to play for a minute. Emma has 7 8 credit. How many minutes can Emma play? Think about the situation… 1st: What do we have? 7/8 2nd:What fraction size are we cutting it into? 1/4 Apply the standard algorithm… “Multiply the Reciprocal!” “Stay, Change, Change!” Write it as a multiplication problem. Change improper fractions into mixed numbers and/or simplify your final solution. 7 8 ÷ 1 4 7 8 ÷ 1 4 = 7 8 × 4 1 = 7×4 8×1 = 28 8 =3 4 8 =3 1 2

Your Turn! Good Luck! I bet you get MORE than a fraction right!  Natalie is making scrapbooks for friends. She wants to decorate each scrapbook with 2/9 yard of ribbon. She has a spool with 2/3 yard of ribbon left on it. She plans to use all of the ribbon on the spool. How many scrapbooks can Natalie decorate? Hints: Think about the situation… Draw a model, create same size, full bars 1st: What do we have? 2nd:What fraction size are we cutting it into? Apply the standard algorithm… “Multiply the Reciprocal!” “Stay, Change, Change!” Write it as a multiplication problem.

There are 3 pieces of 2/9 in 2/3 of a yard! Review your work! Review your work! Review your work! Analysis steps that you completed correctly and determine which steps need more practice and attention. Think about the situation… Draw a model, create same size, full bars 1st: What do we HAVE? 2/3 of a yard 2nd:What fraction size are we cutting it into? 2/9 of a yard 2/3 of a yard 2/9 of a yard THINK! How many 1/9 fractions do you want TOGETHER? TWO 1/9 fractions= 2/9 SOOOOO…… How many 2/9 fractions are in 2/3 of a yard? Apply the standard algorithm… “Multiply the Reciprocal!” “Stay, Change, Change!” Write it as a multiplication problem. 2 3 ÷ 2 9 = 2 3 × 9 2 = 2×9 3×2 = 18 6 =3 There are 3 pieces of 2/9 in 2/3 of a yard! 1/3 Don’t have this piece! 1/9

Congrats YOU have completed Lesson #1 of dividing fractions by fractions!