Hey guys, it's Ms. Perrenboom again. Alright, we are on day two of learning
target six beam and we are continuing to write and solve proportions. Alright, so
let's look at this 1st example here. You're going to order pizza for a
birthday party and decide to order 2 pepperoni pizzas for every 3 cheese
pizzas. How many cheese pizzas were ordered if
you bought a total of 20 pizzas? OK, so there's a lot going on in this problem
and we really need to think about the labels that we're giving to each number
and make sure that we're making a comparison that makes sense. So first
thing I notice is that I've got this ratio of 2 pepperoni pizzas for every
3 cheese pizzas. OK so that gives me the ratio 2 to 3. However, when I
then look at the question that's being asked I want to know the number of
cheese pizzas. OK, well we've got cheese here in our ratio, that I bought if I
bought a total of 20 pizzas. OK, so I've been given this piece of information
about total pizzas ordered. Notice that that is not either one of those labels
right? Neither of these numbers represents a total amount of pizza. So
what we need to do is, we need to come up with a total number of pizzas based on
this ratio of 2 to 3. So let's say I actually bought 2 pepperoni pizzas
then that means I would have bought 3 cheese pizzas, which together would
have given me a total of 5 pizzas. OK, so now I have these 3 separate
numbers right? I've got 2 pepperoni pizzas when I buy 3 cheese pizzas
giving us a total of 5 pizzas. So the question again is comparing cheese
pizzas to total pizzas. So using that information I'm gonna pick out 3
cheese pizzas for every 5 total pizzas. So notice I didn't need to use
this 2 for pepperoni pizzas. I needed it to help me get the five but I'm not
actually gonna use the 2 in the proportion that I set up. OK so now for
our 2nd ratio. So 3 cheese pizzas for every 5 total pizzas and I know
that I've actually bought 20 total pizzas. So that 20 is gonna go in the
denominator of my 2nd ratio and I'm
finding out how many cheese pizzas were ordered. And so that means x, or my
unknown, is in the numerator. OK so now to look for a relationship. So just like
yesterday we want to be looking for either a horizontal or vertical
relationship between these quantities. So I'm gonna say I know that 5 times
4 is equal to 20 so I'm gonna do the same thing to the top. 3 times 4. And
that's gonna give me 12. So that means I would have ordered 12 cheese pizzas and
then, when we think about that, that also would mean that we would have ordered
then 8 pepperoni pizzas, right? And that 8 to 12 for pepperoni to cheese, but still
maintain that same ratio of 2 to 3. Alright let's take a look at another one.
Alright, 3 out of every 7 students in Mrs. Green's room are girls. How many
girls are there in the class if there are 24 boys in the class? OK, so again
let's kind of pick out what information we have. I know 3 out of every 7
students are girls. OK, so that means there's 3 girls out of every 7
total. OK that's the information that I have. OK what are we being asked? We are
being asked how many girls are there if there are 24 boys in the class. Well I
wasn't given any information about boys, but if we use some common sense here bet
we can figure it out. If I have 7 total kids and 3 of them are girls
and that's gonna mean the other 4 would have to be boys right? Cuz then the
3 girls plus the 4 boys gives me that total of 7. OK, so I want to
compare girls to boys right? That's what my question is asking me to do so I'm
gonna take this number 3 for the number of girls and I'm going to take
this number 4 for the number of boys and that's the ratio that I'm gonna set
up. OK, so I want my ratio to be 3 girls for every 4 boys so then I know
that there are actually 24 boys in class, So 24 that's gonna be the number of boys
so that goes in the denominator of my second ratio. And x is on top or finding
the number of girls. OK, so again look for a relationship
that we can use. I know 4 times 6 is 24 so I'll do the
same to the top 3 times 6, that's gonna give me 18. So there would
be 18 girls and this is Green's classroom.
OK, so now that we've gone
through 2, again they are the same types of problems that we were doing the
other day it's just now there's like a little bit more work to do to get that
initial proportion set up. So here are 2 more questions for you to answer on
your own. OK, the first 1, number 3, a paint mixture calls for 3 gallons
of white paint to be mixed with 1 gallon of red paint to make the shade of
pink that you want for your house. So if I need a total of 32 gallons of this
pink paint, how many gallons of white paint will be used? OK, number 4 an
employee working at an electronic store earned $3,582
for working 3 months during the summer. What did the
employee earn for the first two months? OK, so you're gonna go
ahead and pause and work on these 2 questions and get your answers written down and we
will go over these tomorrow in class. When you're done with these 2 then
you have your reflection at the very end. So hit play when you're done. OK,
so finally to wrap up, make sure that you write down 1 thing that you either
learned or we're reminded of and then any questions that you might have so
please try to write at least one thing for each and we will see you tomorrow
back to class. Thanks for watching


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