EXT 3-6 Sampler

47 Objective17: To add fractionswithunlikedenominators. PD Materials: FractionBars orFractionStrips (Master 16) AddingwithFractionBars The following activityprepares students todiscover anduse thepatterns or rules for finding the lowest commondenominator and changing the fractions into equivalent fractions. Writeon theboard: Khalid ate⅔of a candybar. Mari ate¼of the same candybar. Howmuchof the candybardid they eat? Allow each small group time todiscuss possibleways to solve theproblemusing a set of FractionBars.Have students explain their thinking.Guide students todiscover the GoldenRuleof Fractions: To addor subtract fractions, the fractionbarsmust be the same color.Have studentsdisplay ⅔(yellow) and¼(blue). Canweput ayellowbarand abluebar together? (no, theymust be the same color, i.e., divided into an equal number of parts) Have students find all equivalent fractionbars for⅔and ¼. Change⅔and¼to the same colorbar.What colordo younowneed touse? (change thebars to theorange 8⁄12 andorange 3⁄12) Howmuch is 8⁄12+ 3⁄12? (11⁄12) Writeon theboard: Writeon theboard: Connor saidheused⅝of anotebook formath and¼of this samenotebook forhistory. Is this possible?Explain. Discusshowyou candetermine if this is possible. (When the2 fractions are added theymust be equal toor less than1.)Repeat theprocess of having studentsuse fractionbars to find the sum. Howmuch is⅝+¼? Writeon theboard: Is itpossible thatConnorused the samenotebook for mathandhistory? (yes) Howdoyouknow? (the fractions addup tobe equal toor less than1) Read the information at the topof thepage together. Have studentsdemonstratehow to solve theproblemwith fractionbars, emphasizing the “GoldenRuleof Fractions:” You cannot addor subtract fractionsunless theyare the same colorordivided intoanequal numberofparts (the denominators are the same). Have studentswork theproblemswith fractionbars. Hit to 2 Deal eachplayer 1 fractionbar face down and 1 fractionbar face up. Players “stand” or “hit” to get as close as possible to 2without going over 2. The dealerwins ties. Try tobeat the dealer. Skill Builders 17-1, 17-2 - 5 8 5 8 1 4 2 8 7 8 Lesson12, 5ETeacherGuide 38 38 ©Math TeachersPress, Inc.,Reproduction by anymeans is strictly prohibited. AddingUnlikeFractions Lisahas completed _____of her weekly practice time. Add. Lisadid of her weekly piano practiceonMonday. She did of her practiceonTuesday. Howmuch of her weekly practice timehas she completed? 11. Jane ate of a candy bar and Ray ate of the same candy bar. Is this possible?Explain. _______________________________ _______________________________ 9. Julie rode her bike of amile to school in themorning. After school she rode of amile to her after-school job. How far did she ride inall? ___________ 10. Mary bought of a pound of caramels and of apoundof chocolate creams. Howmany pounds of caramels and chocolate creams didMary buy? __________ 12. Jess ate of a pizza. Jack ate of the same pizza. Dennis ate of the samepizza. Is this possible? Explain. _______________________________ _______________________________ + + = = or Findall fraction bars equivalent to Has thesamenumber ofpartsas 1. + 5. + 2. + 6. + 3. + 7. + 4. + 8. + 2 6 2 10 8 12 3 10 1 4 1 12 1 8 3 12 3 6 5 10 3 12 4 10 2 4 6 12 4 8 4 12 5 6 7 10 11 12 7 10 3 4 7 12 9 10 9 12 9 12 4 12 14 12 9 12 3 4 5 12 3 12 2 12 3 4 5 8 7 12 No. They equal more than 1. Yes. All three amounts can be part of the samewhole. of amile of a pound = = = = + + + 5.NF.1, 5.NF.2 AddingUnlikeFractions It is easier to remember you can’t addor subtract fractionsunless theyare the same color than to remember theymust have the samedenominator. Grade5