Discounts!

We've been learning about percentages and shopping discounts. After solving several "percent off" porblems, we created our own. Here they are:

1. Leo dcided to buy 12 dog bowls for a dog show. Each dog bowl cost $10. The store had a 10% discount. How much did she end up paying after the discount? (By: Angelina)

2. To get 5 of Adam's lollypops it costs $2. If I promise not to raid Adam's room for one week, the lollypops will be 15% off. How much will they cost if I do not raid his room for a week? (By: Sydney, Adam's sister)

3. You can get a dog for 8 payments of $480. If you want to pay for the dog all at once, you will get a 25% discount. How much would the dog cost if you pay for it all at once? (By: Will)

4. At Southern Season you bought a jar of ketchup that originally cost $4. It was in the "Summer Sale" bin and marked "25% off." How much did you actually pay for the ketchup? (By: Michael)

5. Joe wanted to buy a apartment that cost $20,000. He happened to have a apartment coupon, so he got 10% off the price. How much did he save? How much did it cost with after the discount? (By: Justin)

6. Fred is selling a 100 crate gold bar. He says you can give him $1,000,000 or give him a sandwich and get a 35% discount. How much money would the gold bar cost if you give Fred the sandwich first? (By: Albert)

Try some of them out and post your answers below.

A Multiplication Problem

Hi! We're Kevin and Simon. This is the equation 11 x 32 = 352 using inch cubes. We did this by combining Justin, Jackson, and Ari's idea (see the Centimeter Cube Challenge) but with inch cubes. First we solved the problem and then turned the inch cubes into numbers. Then we finished the problem and took a picture. Here it is: 

Exploring Area

Last week we explored area. We were given a certain area and then asked to create a geometric shape on a geoboard to represent that area. We then had to color in our shape on grid paper. Here is some of our work:

This irregular polygon has an area of 8.5 square inches



This irregular polygon has an area of 7 square inches



This irregular polygon has an area of 10 square inches




Here is one sample of completed work.
This student chose to label each square so that it was very clear what the area was.




Here is another work sample.
You can see there are some irregular polygons and two rectangles.


We noticed that there are often many ways to represent the same area. For example if you are making a figure with an area of 12 square inches, you could have a 1" x 12" rectangle, 3" x 4" rectangle, or a 2" x 6" rectangle. It is also possible to create an irregular polygon with an area of 12 square inches.

We also noticed that when working backwards from a given area, the rectangles you can make are the same as the factors for that number. For example, the factors of 12 are 1 and 12, 3 and 4, and 2 and 6. We also made a connection between area and arrays (a way we use to solve multiplication problems before we memorized our math facts). It is neat to see how it all goes together.

Is there anything you notice that you would like to share with us?

A Geoboard Sea Monster!!!

Hi! I'm Jackson! This is a design I made our of four 5 by 5 geoboards and a bunch of rubber bands making a sea monster with a line of symmetry down the middle. The main body is a huge reqular octobon, one swuare, and eight right triangles. The head/mouth is made of ten right triangles, two parallelograms, and three straight red lines. The tail was made of one long straight yellow line, two parallelograms, and three triangles. Each arm is made of one right triangle, two squares, one tall trapezoid, and four green lines.

Accuracy and Precision

I cannot explain this without examples, so here is one.

A man is throwing darts at a dart board. All his darts land in a cluster, each dart within a milimeter away from each other, but far away from the bullseye. He is very precise, but not very accurate.

Here is another example: Your scale at home says you weigh 81 pounds. Then you got to a chekc up at the doctor's office and the doctor's scale says you weigh 81.4 pounds. Both scales are accurate, but the doctor's scale is more precise because it can measure more after the decimal point than your scale at home. 81 pounds is still accurate, but 81.4 pounds is more precise. Your scale weighed to the best of its abilities, wich, in this case, has nothing after the decimal point. But if your scale says you weigh 8 pounds, that is not accurate because accuracy comes before the decimal point. Precision comes after the decimal point. 1.000 is not more accurate than 1, but it is more precise because the more digits there are after the decimal point, the more precise that number is.

Confused yet? Oh, and what does this mean for what we told you about pi and using 3.14 to solve problems?

Alana

Area and Perimeter

Hi everybody-                              

         We wrote perimeter and area out of geoboards.      



The perimeter is the distance around the shape.  To find the perimeter you add up all of the side’s length and see how large the perimeter is. 

The area is multiply the height and the base for a rectangle, square, or parallelogram or you multiply the height and the base divided by two for a triangle.

Thanks!

David, Zachary, and Christopher



Centimeter Cube Challenge

Hi everybody-

                I’m Justin and I decided to make a project with my friends, Ari and Jackson. We decided to write “CENTIMETER CUBES” out of centimeter cubes and “INCH CUBES” out of inch cubes. (Get it?)We were inspired by our teacher, Amanda. She was teaching a lesson about centimeter cubes and finding the area and perimeter. We completed this task in about eight days. We decided to write “INCH CUBES” after we wrote “CENTIMETER CUBES”.

So what is the surface area of the centimeter cubes? What's the perimeter? What is the surface area of the inch cubes? How about the perimeter? Don't forget to use the correct units to label your answer!

Speedy Sam

Hi. I'm Alana and this is a math game we sometimes play in our class called Speedy Sam.

Two players stand back to back and a third person, the caller, calls a math fact SLOWLY. As each part of the fact is called, each player takes a step forward. Then, after the word "equals" is called, the players whirl around and shout the answer as quickly as possible. The person who says the correct answer first is the winner and another challenger steps up to try to beat them.

For example, if the fact is 3 x 6, the caller would say each part separately. The caller says "3." The players take a step. The caller says "times." The players take a second step. The caller says "6." The players take a third step. The caller says "equals." The players take a fourth step, turn around, and yell the answer.

We plan on making a video demonstrating Speedy Sam. Until we get it made and posted, please comment if you are still confused.

Circles and Pie

Okay not Pie, Pi!

Hi I'm Will and I'm going to show teach you about finding the area of a circle.
Here's the formula: or in words, Area equals pi times radius squared

Let's say the radius of a circle is 3 cm.
First multiply the radius by the radius. 3 x 3 =9
Then multiply this answer by 3.14 (the short version of pi). 9 x 3.14 = 28.26 cm.
So your answer is the area of a circle with a radius of 3 cm is 28.26 cm.

Here's some words to rememember when you are solving the area of a circle:
Pi is 3.141592... when solving math problems we use 3.14
Formula- a way of finding the perimeter, area, etc.
Radius- line from the center point of a circle to a point on the outside of the circle

Now makes some example of your own, and share them with us by leaving them in a comment below.

Thanks!

Random Math Facts

Did you know?

1. 

This symbol, pi, is equal to 3.14159265358979323846....

2. A sphere has two sides. However, they are one sided surfaces.

3. Among all shapes with the same perimeter, a circle has the largest area.

Do you have any random math facts? Share them below.

Thanks,
Will

Screen Casting: Basics of Multiplication

Hi! We're Ari and Lena. We created a screen casting to teach you some basics about multiplication. We hope you enjoy it! Thanks for watching!

Screen Casting: More Lattice

We're Morgan and McKenna and we created this screen casting to teach how to solve multiplication problems using the lattice method. Enjoy!

Screen Casting: Comparing Fractions

My name is Sydney and I am teaching how to compare fractions. To teach this I made a screen casting because with screen casting I can narrate the movie. A challenge I had was I could not clearly narrate the movie. To solve the problem I selected a different microphone to record my voice. I enjoyed this project because it was not too hard, but it was kind of challenging.

Screen Casting: Adding Fractions

My name is Alana and I will be teaching you how to add fractions with this screen casting. I chose to make a screen casting because I had only done it once and I wanted to do a harder, more complicated one. First I made the slides with the Smart Notebook on the laptop. Then I recorded my voice to the slides, but it was too quiet and there were lots of background noises. At the end I rerecorded it in a closed room and I spoke louder. Some parts of this project were frustrating and hard, but in general it was fun.

Movie Time! Converting Fractions to Decimals

Hi! I’m Cal, and I’ll be teaching you how to convert fractions into decimals. I’ll be teaching this through a PowerPoint, which I converted into a video. I chose to teach it this way because I thought it would work very well. A challenge for me was how to convert my PowerPoint into a video. I overcame it by asking Katie, the computer person, if she could help. I liked this project because it’s better than math pages and I like technology and would like to learn more about it.

Screen Casting: Equivalent Fractions

Hi! I’m Caroline and I am going to teach you about equivalent fractions. I made a screen casting video. I made a screen casting video because I wanted to talk and give time for the people understand what I was talking about . A challenge I had was when I was trying to preview it didn’t work when I was logged in as anyone else. It only worked when I was logged in, because I forgot to finish it! I enjoyed  this project because I love to see other people’s work, and I thought it was a lot of fun.

Movie Time! Pattern Block Equivalencies

Hi-

I’m Justin and I’m teaching you about equivalent fractions. I’m going to teach you this by making a stop-motion video with pattern blocks. I decided to teach you by making a stop-motion because it was a very good way to teach you for the topic Amanda assigned me.  I thought this was hard because I had troubles trying to get the text onto the pictures. I ended up fixing it in PowerPoint.  I liked this because I enjoyed being able to make a stop-motion video.

Screen Casting: What is One?

Hi! I’m Ana. Today I will be teaching you about if you have a fraction how to figure out what is one whole. Here is an example:

23 goldfish are equal to one fourth of the goldfish, and you have to figure out how many goldfish there are in all? Watch the video and try to answer the question, then after enough people have guessed, I’ll tell you.

I decided to make a screen casting video because I think that it is the best way for people to absorb the math in it. The process was hard but fun. The first thing I had to do was create the slides, that took up a lot of my time because I had to do it on a laptop not the smart board (which by far is easier). Then I got to record on the smart board but you couldn’t here me so I had to re-record with some struggles because it wasn’t on the right microphone (Katie helped me with that). Then I picked music, made credits and edited. I had a lot of fun and I hope you will to with all our new fraction entrees. So I hope you enjoy the video.

                                                 

                                       -Ana

P.S. Kaite is spelled  in the videos credits (is supposed to be spelled Katie)