Friday, October 24, 2014

Hashtag Closure

This was really fun.  My students loved it.  And it was different.  It brought out relevance and personality to the class.  It also gave a voice to some of my students.  Give it a try.  Thanks to my colleague Mary Martin (Via Steve Stack)  who gave me this idea.  

Ask your students to make a hashtag summary for the topic of the day (or week, or unit, or ?)  I used it as I closed the day out. Then ask them to share them out with the rest of the class.  You can share out results on the board.  Then have students vote on them.  Students loved it.  For those of you who do not know what a hashtag is…A hashtag is a word or an unspaced phrase prefixed with the hash character, # , to form a label.  Hashtags are used in social media as a type of tag to group information.  #postseason #edchat

I did this with my precalculus student's and they put a few things that were terrific and some things that were just plain funny.  We were studying rational functions and vertical asymptotes.
#ZeroDenom  #FindTheZerosInTheDenominator Some funny ones were #AskMrSladkey #Desmos.  I was talking about something the next day in class and said "remember the hashtag closure" from yesterday.  It was a great brain trigger.

Mary taught me to use to share out results.  It is so easy.  I had never used it before last week.
  •          Log into  and then teacher sign in. Go to Sign up.  Then go to profiles and change your room name to your last name.
  •         Go to quick question.  Then click Short Answer question.  Type in your question.  Require students names.  Click Start
  •         Have your students go to and go to the student sign in.  ( I had my students use their phones)  Have them use your room name.  They don’t need to sign up.
  •         When they answer the question it will show up on your screen for all to see.  After all have entered their answer, then vote on the result.

I hope you can give it a try next week.


Sunday, October 5, 2014

Shifting to the use of Desmos and Geogebra Online Graphing Calculators


Wow.  This is fun.  I can't believe how easy it is to put math into our student's hands.  It is fast too. With a simple url link I have given my students many activities in seconds that takes them DIRECTLY to the concept.  This year I have really shifted my thinking away from the hand-held graphing calculator to the online calculators Desmos and Geogebra.  I use both for different purposes.  This post is a little about my journey this year.

For my day to day work, I have my students take out their smart-phones, or their iPads, or their school administered tablets and use Desmos free online graphing calculator.  For class activities, I often use Geogebratube.  This is easy way to challenge students with a math "scenario" online.

This week we were reviewing quadratics and I gave this "challenge" to my classes.  They had to navigate a MAZE with lines and parabolas.  Here is the actual activity that I gave them.    Notice it is an easy to use to type in link.  (This is called a url alias and I use the free website called to set this up)   I  also made a short video for help clues too.  Not everyone needed it. 
Here are a couple of comments my students have made about Desmos.  One was how he liked Desmos because the he could see both the graph and the equation at the same time.  He didn't have to go back and forth from the equation to the image.  Another student said they like the fact that they could find the graph so easily.  You can just use your fingers to pinch the screen and you can locate the graph.  Whereas while using a handheld graphing calculator you have to go back and forth from window to graph, to finally get the right graph screen.
This is how one student solved it.  There is so much math here.  The students really talk the talk too.

One video that really inspired my use of Desmos was by @bobloch on twitter he shared this demonstration on inequalities.  Check this out.  

I have always had a hard time explaining increasing and decreasing.  This turtle Geogebra activity really helped my students visualize what increasing and decreasing is and how it is represented.

You can see that there is a ton of material that can be used with Desmos and Geogebra.  Go and explore.  Let me know how it goes.  My twitter name is @dsladkey.  I'd love to hear from you.


Wednesday, June 11, 2014

5 Random Technology PD (Professional Development) Thoughts

Technology is tricky. Everyone is at a different place. So PD (Professional Development) time is very important. Here are a few random thoughts that have been rolling around my head since our latest Technology PD day.

1.  Whole group "how to" technology training rarely works. Most of the time 1/3 of the people are bored, 1/3 are with you and 1/3 are completely lost and frustrated. Group "how to" technology training certainly has it's place at times but should be avoided if possible.  

2.  Let the computer teach the "how to" technology through tutorials and a self guiding pace.  Offer 1 to 1 help for the very few who can't do self guided. 

3.  Design PD activities that model good teaching practice (above the SAMR bar or higher in Blooms taxonomy) and forces the use of the technology within the activity. This way you can show a good teaching idea and you can help them learn a new technology. 

4.  More than a half day of whole group technology PD is too much.   If you want a whole day of PD then maybe half the day is spent in a whole group atmosphere and half is spent in very small groups  or with a partner or alone.   

5.  I think some self reflection time must be built in to our PD.  i.e.  15 minutes of journal time reflecting on the things you have learned and the questions you still have out there.   We put a lot of emphasis on closure in the classroom, and rightly so. Self reflection is a type of individual closure that will help us process what we've just learned and help us remember it. 

I welcome your random thoughts or comments. 

Thursday, June 5, 2014

10 Reasons Why I think the TI-84 is on the way OUT!

Yesterday a colleague told me she overheard some students talking about how they never used their TI-84 at home.  She pursued the discussion and they said that they use DESMOS the online calculator all the time at home.   I think the use of it will go away slowly.  But it will happen.

The TI-84 (or TI-83) has been a fixture in my classes for many many years.  It has been a requirement on my syllabus.  It is something that I would daily ask my students to take out and work with.  I can't count the number of tutorials I've made to help use the TI-84.  It has been a go-to device for CONCEPTUAL learning.  But things are changing.

My Prediction.  Our school will not be requiring the TI-84 in the school year 2015-2016.  I have no authority to make that call.  I'm just making a prediction.  Our school goes 1 to 1 that year.  In my opinion, the days of every student having a TI-84 are going away.  Why?  Because other things are passing it up. And the thing that is passing it up is NOT another Graphing Calculator.  It is the Internet with web based interactions and  apps.


10 Reasons why I think the  TI-84 will NOT be required at our school in 15-16 
1.  Touch Screen
Students are getting frustrated with the TI-84 because it doesn't offer a touch screen.  The touch screen on a SMART-Phone or a tablet helps with finding the right window, editing data, sliders, and a bunch of other cool things. Also, the mouse is even better than the awkward navigation system of the TI-84.   I have tried to physically touch the TI-84 screen many times.  That's embarrassing.

2.   Ease of Use
As technology gets easier and easier to use.  The TI-84 seems to be more and more confusing to use.

3.  Size of Screen
A computer screen is a lot bigger than a TI-84 screen.  And a SMART-Phone screen is equivalent to a TI-84 screen.

Why should we ask our students to pay $100 if our students will have constant access to a district owned device?  (i.e. tablet, Surface or Chrome book)  EVERYTHING that a TI-84 can do, a district owned device can do.

5.  1 to 1
Our district will likely go 1 to 1 in the 2015-16 school year. Every student will have a district owned device like a tablet at that time.  It doesn't make sense to have both devices.

6.  Data Exchange
The TI-84 system of exchanging data is old and outdated.  Basically it is useless.  For me to get something onto my student's calculator is nightmarish.  (It used to be really cool)  But, because the transfer of data is so easy with phones, and computers, and  tablets, that the technology of the TI-84 is really getting in the way of collaboration.  Remember, it used to be so cool to give your students a program or some data via the cord that goes between the calculators.  There is way too much teaching time wasted on account of this.  The students know a lot of ways to get information to each other that does not require a cord.

7.  Finding the Right Window
I have forever said that finding the right window is a great math skill on the TI-84.  However, I think I have been bypassed with the love of this skill.  The ease of a computer or tablet to get the right screen is far superior to the TI-84.

8.  Animations/Sliders
Sliders offer a hands on approach to math.  It encourages participation with the activity, with low risk high reward outcomes.

9.  Apps and Programs
The Internet math based apps are gaining momentum.  It's getting easier and easier to use math notation on the Internet.

10. Internet Based Math 
Desmos, Geogebra, LaTeX, online calculators etc.  This is just the beginning.  

Standardized Tests are the problem. I don't know what will happen with these.  The TI-84 has been a fixture for an acceptable device on the standardized tests for a long time.  With the PARCC online testing, this might be changing too.

TI-84 may you Rest In Peace.  It is time to move on.

Wednesday, May 28, 2014

Graphing Polar Equations with Desmos (online graphing calculator) and Padlet (online bulletin board)

This was easy.
We had just covered polar equations in precalculus. I then told each student they should make a cool design using 10 or less equations. Wow. They really loved it. They explored well beyond what we covered in class.

1. Log into and either sign in or sign up.
2. Make a desmos polar graph using 10 or less equations.  Use r= equations and use theta as your variable. Also you can use a polar background if you like.
3.  They should save their graph in desmos. (you can only do this if you are logged in)  Then click on share which gives you a link. Save that link.
3.  Then they had to log into the site URL that I gave them. Here it is:  They double click anywhere on the screen to make a post. I had them put their name and then put the desmos link right in the post.   I have put a picture of the padlet site.

Give it a try and let me know how it goes.

Tuesday, March 11, 2014

What is the Weight of the Snow You Shoveled this Winter?

A colleague of mine gave me an article today from the Chicago Tribune called "One man's snow-shoveling total: 25 tons (and counting)"   Take some time and read it.  I loved it.  There is a TON of math in this.  Pun intended.  Wallberg (the author) challenged us to find the amount of snow that we have shoveled on our own driveway.  So, being the math geek that I am, I did it.  Here is my work.

1.  I found the area that I shovel on my driveway. Use this site:  Free Map Tools This site is really cool.

2.  Let's change snow to water. Wallberg (the author of the article) uses a 15 inches of snow to 1 inch of water ratio.  So we have had 75.2 inches of snow this year so far divided by 15 will give us the amount of water in inches that we have had this winter.  That is 5.01 inches of "rain" that fell as snow.  That is (5.01/12) of a foot.
3.  Ok now lets figure out how many cubic feet of water that is.  I took the area that I found for my driveway from the cool website above and multiplied that by (5.01/12).  That is 1085 square feet times (5/12) foot to equal the number of cubic feet of water that is on my driveway.  Remember that the (5/12) foot will be changing as there is more snow predicted tonight.  That would be roughly 453 cubic feet of water.

4.  One cubic foot of water weighs 62.4 pounds.  If you multiply 452 cubic feet from above by 62.4 pounds you get roughly 28,267 pounds of snow (water).  Yes that is over 14 tons of snow that I shoveled!  I just patted myself on the back and said "Good Job David".

They will need to use this info.
1.  Find the area that you shovel on your driveway.   Free Map Tools 
2.  Use 15 inches of snow equals 1 inch of water ratio.
3.  Use 62.4 pounds per cubic foot of water.

The beautiful part of this problem is that their are a lot of ways to come up with the answer.  Wallberg (the author of the article) found the weight of 1 square foot of water by 1 inch high.  He used this to get the the weight of 1 square foot of water for whole seasons worth of snow (water).  I love this problem because it gives the students some ownership of the work.  Give it a try.  I certainly will.

Thanks to Twitter: @mattwalberg1  for writing this cool article.

Thursday, February 27, 2014

ICE Conference 2014

I attended the ICE Conference (Illinois Computing Educators Conference) today.  Here are some of the things I am going to use.

1. Keynote Speaker: Mike Muir from Maine  twitter @mmuir
"It's about the learning not the stuff"
"We should have a Pedagogical Focus not a Tech Focus"
"It's not a Formative Assessment it is Formative Feedback"
"Create great learning with Technology"

2. Using Digital Tools as Assessments for learning:  Jamie Gourley and Josh Zwart @Josh_Zwart
Hand Out
Quizlet is an easy program that can work for math.  Check out Josh's trinomial example example:
I also learned that you can put in videos to Google Forms.

3.  Cool Tools for the BYOD Classroom:  Tammy Worcester  @tammyworcester Evernote tip sheet
This is a feedback system that you can draw pictures and submit them to the instructor.  I tried it and it is really cool.
She shortened urls and made a QR code with a Google Document.
She made a Google Form and had us enter our name and the place we were born.  She then took the data and put it in a site called  Instructions are here:
She did a different presentation with Greg Tang and I thought you would like to see some of that info:  Evernote Handout

4.  I saw Nancy Norem Powell  @NAPmath doing a session on SMARTBoard Wigits  and
I learned about how there is a beta version of Extreme Collaboration which was taking information from any device (not a clicker) and using the info on the SMARTBoard.  Click here on how to get it

5.  I met Tony Schlorff who told me about the SMART LightRaise™ interactive projectors which does not need the board.  It shines on the wall and you can draw using your finger.  AMAZING.  He said it costs about a third less than the regular SMARTBoard.

6.  Lastly, I went to a workshop with Our Journey in “Going Google…”  Matt Dusterhoft, Pat Deane & Kate Fahey  Lockport Township District 205  Click here for their handout  twitter:  Kate:@EdTechKate Pat: @ITDeane  Matt:@mduster