Saturday, September 27, 2014

Estimating, Error Rates & Plotting

Estimating, Error Rates & Plotting



Take your class outside and designate a single starting point. From that point throw 5 or 6 objects at various distances. Next, ask your students to estimate how many feet each object is from the starting point. After they have estimated each object have them measure the length to the nearest foot and record their data in a table such as that below.



Next, have each student calculate their error rate using the formula (actual) – (estimate) / (actual) and change their decimal to a percent.




Finally, have the students plot the points on a coordinate (x,y) plane and form a scatter plot. It’s best to have them graph the equation y = x so that they can see their error rates.  








Friday, September 19, 2014

Scatter Plots With Ramps

Scatter plots move in two dimensions which allow students to see changes in slope as well as the relationship of the two data sets. The study of scatter plots lends to a lot of fun experiments and can also serve as a great segue to discussions on proportionality or the coordinate system.

Ramp Height & Distance Traveled.

We decided to build ramps and plot the height verses distance traveled. We increased the ramp in (approximately) one inch blocks and rolled a golf ball off the ramp to measure the distance traveled. See Below. To get better results we took the average of three rolls. Lots of FUN! 


Saturday, September 13, 2014

What To DO With a Handful of Pennies? Measures of Central Tendency

A good icebreaker to use when introducing Measures of Central Tendency (Mean, Median, Mode, etc) is to grab a handful of pennies from your vehicle and lay them out on a table and have your students work in groups to place them in order of date from least to greatest (if you have a large class you may need multiple handfuls of pennies).  
Next, start collecting data.
Mode can easily be seen by the largest stack.
Median, Range, Q1, Q3, IQR can also easily be found
Mean is slightly tougher unless you allow your students access to a calculator
Next, have your students create a dot plot of the data
Finally, have your students pick 5 pennies for their homework. Tape the pennies to their worksheet so that they can read the date (see pic below).