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Warm Up:Warm Up:
•Give examples and/or counterexamples toshow whether each statement is true or false.
•Let 0 < a < b < c.
•a/b < b/c ?
•a/c > c/a ?
•c/b < b/a?
•(ac)/b = (ab)/c ?
Agenda
•Yamalet Video
–Review Word Problems
•Alexa Video
–Review Pictorial Models
•3 Practice Problems
•Assign homework
Yamalet
Watch the video.
On page 21, the follow-up questionsask us to use a pizza scenario tounderstand how 3/8 could be used as aratio, an operator, and a quotient.
Word Problems
•Write word problems for 2/5 and 5/2 for each:
–Part of a whole
–Ratio
–Operator
–Quotient
We will look at some examples then take some timeto write our own.
Word Problems
•Part of a whole: The question must statewhat the whole is, and the parts must all bethe same size.
•Ex: I have 4 marbles, but 3 of them arescratched. What fraction describes thescratched marbles? (3/4)
•Ex: I have 14 plates, but four are coveredwith grease. What fraction describes theclean plates? (10/14 or 5/7)
•You try one.
Word Problems
•Ratio: The question must describe thecomparison between 2 quantities.
•Ex: I have 20 socks, and 8 are red. Write aratio describing the red and not red socks.(8 : 12 or 2 : 3)
•Ex: On my homework, I got 6 out of 9problems correct. Write a ratio comparingthe correct and incorrect answers. (6 : 3 or2 : 1).
•You try one.
Word Problems
•Operator: This question asks how a quantityhas changed. If the initial amount hasincreased, then the operator is greater thanone.
•Ex: This year, I have 25 students in Math302A. Next year, I hope to have 20. Whatfraction of my current class is this? (4/5)
•Ex: Last year, 100 students passed Math302A. This year, I hope 6/5 as many pass.How many students do I hope pass?
•You try one.
Word Problems
•Quotient: Either, the answer to the questionis the fraction, or the question describes thedividend (numerator) and divisor(denominator).
•Ex of 5/30: If a family of 30 equally shares 5pizzas, how much pizza should each personeat? (5/30 or 1/6)
•Ex of 5/30: If 300 people share 50 pans ofbrownies, how much should each personeat? (50/300 = 5/30 = 1/6)
•You try one.
Word Problems
•Label each problem as (a) part-whole, (b)ratio, (c) operator, or (d) quotient. If you arenot sure, write not sure.
•Marci had 15 marbles. But she lost 2/3 of them.How many does she have?
•operator
•Jeremy comes from a large family: there were 2boys for every 1 girl. Could he have 12 kids inhis family? Could he have 13?
•ratio
Word Problems
•Beatriz walks 3/8 of a mile.
•Part of a whole (the mile is the whole).
•Kevin planted 16 tomato plants last year. “I’m gonnaplant 2 times as many this year.” How many tomato plantswill Kevin need?
•Operator (the fraction is 2/1)
•At the dog park, 8 dogs had outfits on and 16 did not.
•Ratio
Word Problems
•Mom made 3 pans of brownies to share equally among 36kids. How much does each kid get?
Quotient
Dad has $90 to share equally with 12 grandchildren. Howmuch does each grandchild get?
Quotient
A certain company has 300 workers, and 4/5 of them makeminimum wage. How many workers earn minimum wage?
Operator (note: if the problem said 300 workers and 40 ofthem made minimum wage, then it is part of a whole.)
Alexa
•We will watch Alexa in just a few moments.Look at her work on page 23 for the secondproblem. What do you think Alexa was doingin each diagram?
•Now pick one. Can this picture be used tomean part-whole? Ratio? Operator?Quotient? If yes, say why. If no, say whynot.
Now, we’ll watch Alexa
•Complete parts 1, 2, and part a in yourgroups.
•Now, try part c (skip b for just amoment). Once you found the value for5, explain it in words so that someoneelse will understand.
Alexa
•Now, let’s try part d. Same thing--onceyou get an answer, try to write it up inwords so that someone else willunderstand.
Alexa
•Now, let’s talk about how parts b and care alike, and how they are different.
•Do part b.