DIVIDING FRACTIONS Example: Use TWO yellow hexagons as your whole to solve: QUESTION: HOW MANY s GO INTO? Shade of the whole: Then find of the whole: Then see how many s go into ANSWER = 3! There are 3 s that go into! a) Use TWO yellow hexagons as your whole to solve: 3 Barbara Boschmans/Brian Beaudrie of 8
Dividing Fractions Using Pattern Blocks Example: Use TWO yellow hexagons as your whole to solve: QUESTION: HOW MANY s GO INTO? Shade of the whole: Then find of the whole: Then see how many s go into ANSWER = Since is bigger than, only part of will fit. This part is doubleshaded in the third picture. What part of goes into? of goes into, so the answer is! 3 3 3 b) Use TWO yellow hexagons as your whole to solve: Barbara Boschmans/Brian Beaudrie of 8
Example: Use TWO yellow hexagons as your whole to solve: QUESTION: HOW MANY s GO INTO? Shade of the whole: Then find of the whole: Then see how many s go into Half of / fits One / fits ANSWER. fits into one whole time and then half of it also fits. So the answer is! c) Use TWO yellow hexagons as your whole to solve: 5 Barbara Boschmans/Brian Beaudrie 3 of 8
Dividing Fractions Using Rectangles We can use a rectangle model to divide fractions. Example: Divide. QUESTION: HOW MANY s GO INTO? 3 3 Shade 3 of the whole: Then find of the whole: Now we divide the thirds into fourths vertically and the fourths into thirds horizontally: Note that 3 is equivalent to 8 and is equivalent to 3. One fits: A second fits: :and another part of fits: two out of three parts of also fit ANSWER: s goes into whole times and then two out of three also fit. So the answer is. This is 3 3 the EXACT answer. We can also express our answer in a whole number answer with a remainder: s goes into 3 whole times and then two out of twelve remain. So the answer is remainder. Note: it s OK to do the first two steps at once (i.e. divide your two rectangles into fourths and thirds and then use the same rectangles to go to twelfths). You ll still need to show your last step. Use the rectangle method to divide: Barbara Boschmans/Brian Beaudrie of 8
a) 5 3 QUESTION: HOW MANY s GO INTO? Exact answer: Whole number with remainder answer: b) 5 QUESTION: HOW MANY s GO INTO? 5 Exact answer: Whole number with remainder answer: Barbara Boschmans/Brian Beaudrie 5 of 8
Division of Fractions: Applications Hershey Bar Division Suppose you had one delicious Hershey Bar right now hmmm. Solve these Hershey Bar word problems. Write out the equation represented by the problem. Use drawings and/or write a few sentences that help explain how you arrived at your answer. ) Dirk has one Hershey Bar. He wishes to divide it into groups of size. How many groups will he have? ) Clara has one-half of a Hershey Bar. She wishes to give her three friends equal amounts of a Hershey Bar. How much of a Hershey Bar will they each receive? 3) Kay has two-thirds of a Hershey Bar. She wishes to divide it into groups that are th the size of a Hershey Bar. How many groups will she have? Write a Hershey Bar word problem that models each of the following division equations; then solve each. 3 3 ) ) = 3) = Barbara Boschmans/Brian Beaudrie of 8
More Semi-applied Fraction Problems Show ALL necessary work; don't just write the answer. All answers, when necessary, should be in fractional form (not decimal), unless the answer is a whole number or a natural decimal number (such as using money).. Shelly went to the store to purchase 3 pounds of chocolate. She wishes to divide it into packages that weigh 3 pounds each. How many packages of chocolate at that size can she make? How much of a package will she have left over?. Jodi is having some friends over for lunch. She s going to grill hamburgers, and wants to make 3 quarter-pounders. In her freezer, she has a total of pounds of hamburger meat. How many 8 quarter pounders can she make? What fraction (of a burger) will she have left over? 3. Eli has 5 3 ths of a candy bar. Peyton comes and takes of it. How much of a candy bar does Eli now have?. Eli has 5 3 ths of a candy bar. Peyton comes and takes of a candy bar from Eli. How much of a candy bar does Eli now have? 5. Eli now has 3 ths of a candy bar. He wishes to break it up into three equal groups. How much of a candy bar will be in each group? Barbara Boschmans/Brian Beaudrie 7 of 8
3. Eli has ths of a candy bar. He wishes to divide it into groups that will be equal to of a candy bar. a) How many groups can he make? b) How much of a candy bar will be left over? c) How much of a group will be left over? Barbara Boschmans/Brian Beaudrie 8 of 8