Simple interest

Wow! Today we had five problems which seem to take a looooong time. We learned Simple interest today. The formula is I=Prt, where I = interest, P= principal, r=rate, and t=time (expressed in years).

So here's a sample:

$425 at 5% for 10 years
I= 425*.05*10
I= 21.25*10
I= 212.50

or here's a harder one:

$1000 at 12.8% for 9 months
I= 1000*.128* .75 (which is 9 months out of 12)
I= 12.8*.75
I= $9.60

You only have five problems to do on the worksheet. Make sure you show your multiplying work- you can use a calculator to check it if you want.

Have a great night!
Ms V

Percent of change

Today we worked on finding the percent of change. The formula is change/ original= %/ 100.

So if we have the following:
Original= 10
After =2

we would set up the following proportion:

8/10 = x/100
Solving would show that 800= 10x
Divide both sides by 10 to get 80 = x

And that's that. It's really pretty simple. Just remember that the top number is found by subtracting. It's not in the problem at all.

Homework is p. 363 (6-11) and finish the project 2B which is due tomorrow.

Thanks
Ms V

Project 2B

Today was project work day. We are working on Project 2B- due on Thursday. There are parts to this assignment.
1) Cover- a picture of what you are selling
2) Inside:
page 1) Wholesale + markup = retail price
page 2) Retail price - discount = Sale price
page 3) Sale price + sales tax = Final price
page 4) Commission.

Work neatly, and in an organized way! Tomorrow would be the day to ask any questions!

Good luck!
Ms V

The tale of a price

So today we practiced how to go from a wholesale price, to a retail price (adding the markup), to a sale price (subtracting the discount), to a final price (adding the sales tax). We also practiced finding the commission from the final price.

So- example. We are selling a monkey. We bought it for $200 (wholesale). We mark it up 20%.
20/100=x/200
100x=20x200
100x=4000
100 100
x=40

200+40=240 (retail price)

discount is 10%.
10/100=x/240
100x=240x10
100x=2400
100 100
x=24

240-24=216 (sale price)

sales tax is 8.25 %
8.25/100= x/216
100x= 8.25x216
100x=1782
100 100
x=17.82

216+17.82=233.82 (final cost).


Our salesperson earns a 12% commission.

12/100=x/233.82
100x=12x233.82
100x=2805.84
100 100
x=28.05

Our salesperson earns 28.05.

Tonight all you have to do is decorate the front of your project 2B. Come in tomorrow ready to do the math!

Ms V

Applications of percents

Today we talked about the many applications of percents including tax, tip, commissions, markups and discounts, amongst others. We learned how to find the amount of discount and the amount of markup.

So here goes: Amanda buys a buffalo marked $40. It is on sale for 20% off. How much does she pay?

So x/40=20/100. In other words, what is 20% of 40.
100x=40*20
100x=800
x=8

Now, don't forget the part where we subtract the amount of discount ($8) from the original price ($40). 40-8= 32, so she paid $32 for her buffalo.

The other kind of problem is the one in which they give you the sale price.
Bobo bought an enchilada on sale for $5. It was marked down 10%. What was the original price?

In this case, we have to subtract 10% from 100%, since he is paying 90% of the original price.

So 5/x=90/100
90x=500
x= 5.56 (rounded up from 5.57)

All right, guys. Do your best and be ready to come in and ask questions tomorrow.

Thanks
Ms V

Percent proportions

Today we learned about percent proportions. We used color coding to identify is/ of= %/ 100. Solve with a proportion.

Homework tonight is Percent proportion worksheet. Do at least half of them. In some classes, we split it by boys and girls, in others it was choose any ten. As long as you end up with half the problems done, you're good. Do the work on binder paper, use your colors, and show your work.

Off to math lab!
MS V

More on person-days

So today we took more notes on this whole person-day thing. Here we go:

If you are given people and days, multiply to find person-days.

If you are given person-days, and people (or days), divide to find days (or people)

If you are given people and days, and asked to find people and days, you must first multiply to find person-days, and then divide to get your answer.

We practiced a bunch in class, so you should have no trouble (if you were listening).

Homework: Period 1 is a day behind, so they are doing p. 702 (2-20 even)
Period 2 is catching up, so they are doing p. 702 (2-20 even) AND creating and solving 2 person-day problems,
Periods 3, 5, and 6 have to create and solve three person-day problems.

Best of luck, my little chickadees.

Arrivederci!
Ms V.

Tonight's homework

Oops! I forgot to include the homework: p. 702 (1-20 even). and get your success sheet signed if you didn't. And work on Project 1, which is due on Friday!

Periods 1 and 2, you're a day behind because of the assemblies, so you are working on Project 1, which is due on Monday for you guys.

Hasta la vista!
Ms V

Person- days, squirrel-seconds, and raccoon- minutes

Today we learned about person-days. A person-day is the amount of work a person can do in a day. (1 person x 1 day= 1 person-day). We can do all kinds of fun math word problems with this info. For example, if it takes 8 monsters three weeks to scare 96 children, how many monsters can scare 96 children in 2 weeks? First, we multiply 8 monsters by 3 weeks to determine that it takes 24 monster-weeks to scare 96 children (we multiply, because we are going from monster and weeks to monster-weeks). Then we divide that 24 monster-weeks by 2 weeks and find that it will take us 12 monsters.

8 monsters x 3 weeks= 24 monster-weeks. 24 monster-weeks / 2 weeks= 12 monsters.

Don't worry if it's not 100% clear yet. We'll keep working on this for a while.

Ciao!
Ms V