Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

## Ordering Hats

Click through each representation to see how the display of relative frequency relates to the display of cumulative frequency and their corresponding histograms. Examine how each method is useful for summarizing the variation in numeric data.

## Organizing Data in a Stem and Leaf Plot

A stem and leaf plot is a graphical representation for investigating variation. You will convert an ordered stem and leaf display grouped by tens into an ordered display grouped by fives.

## People Patterns

Observe a line of people, discover a pattern and figure out who should come next. See if you can complete a pattern of 10 people before the penalty word "Pattern" is spelled out.

## The Perpendicular Bisector

Watch as the triangle is reflected over the perpendicular bisector. Practice reflecting other figures.

## Playing with Quadperson

Compare the effects of relative and absolute changes on a picture. Watch what happens to a Quadperson (a drawing of a face made of quadrilaterals) if every line were made half as long or made a half-inch shorter.

## Plot Plans and Silhouettes

Plot out a three-dimensional structure based on two-dimensional silhouettes. Look at the front and side view of figures and use a table to plot out the dimensions that mathematically represent the figures.

## Polygon-Classification Game

Click all the polygons to see which Venn diagram circle they belong to. Then try to determine the correct labels for each of the circles. View non-Flash version.

## Quick Images

Stretch both your visualization and drawing muscles. View a shape for three seconds and then try to draw it from memory. View non-Flash version.

## Quilts

Copy a quilt block made of 16 squares. Each block will have one of the four symmetry types: H, M, B, or S and you choose which you think it is.

## Random Sampling

Sampling can produce measurement bias. See if you can personally select a sample that is representative of a particular population.

## The Rectangle Method

One approach for finding area is to surround the shape with a rectangle, determine the areas of the rectangle and subtract the pieces of the rectangle that are outside the original shape. Use this geoboard to create shapes and determine their areas.

## Repeating Decimal Rings

The process of converting fractions to decimals can help clarify the relationship between the two. Investigate the repeating parts that emerge when you expand sevenths and 13ths fractions into decimals.

## Running a Function Machine

The connected machine is a single function that takes an input, runs it through the network inside and produces an output. You control a network of function machines along with the input and the operation performed by each machine to solve problems.

## Shadows

Can you judge an object by its shadow? Use your mental rotation skills to determine if a shadow can be produced by a particular shape.

## Sharing Cookies

Each of three groups of students tried to figure out how five people can share eight cookies. Observe as the groups comes up with very different solutions.

## Slicing Solids

A cross section is the face you get when you make one slice through an object. See how many shapes you can make when you cut different cross sections of a cube.

## Subdividing Area

To find the area of a shape, surround the shape with a rectangle, determine the areas of the rectangle and subtract the pieces of the rectangle that are outside the original shape. Use this geoboard to create shapes and determine their areas.

## Syntax Store

The colors listed in the boxes represent different parts of speech: noun, verb, adjective, adverb, etc. Figure out which colors represent which part of speech and then use the colors to create proper sentences.

## Taxicab Treasure Hunt

To find a hidden treasure use taxicab geometry, a special kind of geometry that counts in city blocks. Pick an intersection, ask the computer how far it is to the treasure and get the distance using taxicab geometry.

## Testing Your Measurement Bias

There are many sources of variation in data, including random error and bias. Observe the difference between error and bias in this line matching exercise.