Robert Kaplinsky
@robertkaplinsky.com
Math educator. Love helping teachers.
Open Middle co-founder. #OpenMiddleBook author. #ObserveMe creator. Grassroots Workshops President. Get lessons & ideas: http://bit.ly/rkupdates
Open Middle co-founder. #OpenMiddleBook author. #ObserveMe creator. Grassroots Workshops President. Get lessons & ideas: http://bit.ly/rkupdates
Are your students working on parallel and perpendicular lines? Try out these two Open Middle problems from Bryan Anderson:
www.openmiddle.com/equation...
www.openmiddle.com/equation...
www.openmiddle.com/equation...
www.openmiddle.com/equation...
November 24, 2025 at 11:33 PM
Are your students working on parallel and perpendicular lines? Try out these two Open Middle problems from Bryan Anderson:
www.openmiddle.com/equation...
www.openmiddle.com/equation...
www.openmiddle.com/equation...
www.openmiddle.com/equation...
If you've ever wished you had something like X-ray vision glasses that could uncover hidden student misconceptions, you'll love this blog post.
robertkaplinsky.com/x-ray-v...
robertkaplinsky.com/x-ray-v...
November 24, 2025 at 5:03 PM
If you've ever wished you had something like X-ray vision glasses that could uncover hidden student misconceptions, you'll love this blog post.
robertkaplinsky.com/x-ray-v...
robertkaplinsky.com/x-ray-v...
The Hollywood Sign was converted from saying HOLLYWOOD to GO UCLA by some clever UCLA students. I was able to get in touch with one of the students who shared the picture he used to base his measurements off of. Great lesson for calculating area.
robertkaplinsky.com/work/uc...
robertkaplinsky.com/work/uc...
November 24, 2025 at 12:13 AM
The Hollywood Sign was converted from saying HOLLYWOOD to GO UCLA by some clever UCLA students. I was able to get in touch with one of the students who shared the picture he used to base his measurements off of. Great lesson for calculating area.
robertkaplinsky.com/work/uc...
robertkaplinsky.com/work/uc...
Sometimes we keep repeating the same things in education because that's the way we've always done it. What if that's not the best way to do it? Well here's how we can break the cycle.
robertkaplinsky.com/behavio...
robertkaplinsky.com/behavio...
November 23, 2025 at 1:13 AM
Sometimes we keep repeating the same things in education because that's the way we've always done it. What if that's not the best way to do it? Well here's how we can break the cycle.
robertkaplinsky.com/behavio...
robertkaplinsky.com/behavio...
Looking for fun 3-act tasks for elementary and middle school students? Check out these lessons from Andrew Stadel at estimation180.com/lessons/
November 22, 2025 at 8:07 PM
Looking for fun 3-act tasks for elementary and middle school students? Check out these lessons from Andrew Stadel at estimation180.com/lessons/
Tired of students getting correct answers, yet not really understanding what they're doing? Then you should check out the recording of my How To Help Students Become Problem Solvers, Not Math Robots webinar with K-5 & 6-12 versions.
robertkaplinsky.com/norobot...
robertkaplinsky.com/norobot...
November 22, 2025 at 5:45 PM
Tired of students getting correct answers, yet not really understanding what they're doing? Then you should check out the recording of my How To Help Students Become Problem Solvers, Not Math Robots webinar with K-5 & 6-12 versions.
robertkaplinsky.com/norobot...
robertkaplinsky.com/norobot...
Can your high school students create a parallelogram, triangle, or rectangle by listing their points when given one? Find out using these three Open Middle problem from Bryan Anderson.
www.openmiddle.com/creating...
www.openmiddle.com/creating...
www.openmiddle.com/creating...
www.openmiddle.com/creating...
www.openmiddle.com/creating...
www.openmiddle.com/creating...
November 21, 2025 at 11:43 PM
Can your high school students create a parallelogram, triangle, or rectangle by listing their points when given one? Find out using these three Open Middle problem from Bryan Anderson.
www.openmiddle.com/creating...
www.openmiddle.com/creating...
www.openmiddle.com/creating...
www.openmiddle.com/creating...
www.openmiddle.com/creating...
www.openmiddle.com/creating...
Do students feel like scientific notation is pointless? Use this lesson on how many stars there are in the universe. Students must figure out how many stars there are if there are around 100 billion stars in a galaxy and around 400 billion galaxies.
robertkaplinsky.com/work/st...
robertkaplinsky.com/work/st...
November 21, 2025 at 8:07 PM
Do students feel like scientific notation is pointless? Use this lesson on how many stars there are in the universe. Students must figure out how many stars there are if there are around 100 billion stars in a galaxy and around 400 billion galaxies.
robertkaplinsky.com/work/st...
robertkaplinsky.com/work/st...
I need to pick an @openmiddle.com problem for a new presentation and want one that's ideally in the 4th to 7th grade range. What's your favorite problem in those grade levels?
November 21, 2025 at 6:00 PM
I need to pick an @openmiddle.com problem for a new presentation and want one that's ideally in the 4th to 7th grade range. What's your favorite problem in those grade levels?
Professional development often misses the mark when it is more theoretical than practical. Here is a short blog post with thoughts on what the problem is and how we can do better.
robertkaplinsky.com/common-...
robertkaplinsky.com/common-...
November 20, 2025 at 11:34 PM
Professional development often misses the mark when it is more theoretical than practical. Here is a short blog post with thoughts on what the problem is and how we can do better.
robertkaplinsky.com/common-...
robertkaplinsky.com/common-...
Are your high school students working with complex numbers? Try these two Open Middle problems out to see what misconceptions they have:
www.openmiddle.com/complex-...
www.openmiddle.com/complex-...
www.openmiddle.com/complex-...
www.openmiddle.com/complex-...
November 20, 2025 at 1:10 AM
Are your high school students working with complex numbers? Try these two Open Middle problems out to see what misconceptions they have:
www.openmiddle.com/complex-...
www.openmiddle.com/complex-...
www.openmiddle.com/complex-...
www.openmiddle.com/complex-...
This lesson on the best deal when buying carnival tickets gives you a context for connecting ratios to unit rates. Some of the available options are HIGHLY questionable. Will your students spot them?
robertkaplinsky.com/work/ti...
robertkaplinsky.com/work/ti...
November 19, 2025 at 11:14 PM
This lesson on the best deal when buying carnival tickets gives you a context for connecting ratios to unit rates. Some of the available options are HIGHLY questionable. Will your students spot them?
robertkaplinsky.com/work/ti...
robertkaplinsky.com/work/ti...
Help your students think deeply about radicals with this Open Middle problem from Phillip Haislip-Hansberry. www.openmiddle.com/comparin...
November 17, 2025 at 11:33 PM
Help your students think deeply about radicals with this Open Middle problem from Phillip Haislip-Hansberry. www.openmiddle.com/comparin...
Ignite talks are 5-minutes long and have 20 slides that automatically advance every 15 seconds!! It can feel overwhelming so here's how I prepare for one.
robertkaplinsky.com/prepare...
robertkaplinsky.com/prepare...
November 17, 2025 at 5:03 PM
Ignite talks are 5-minutes long and have 20 slides that automatically advance every 15 seconds!! It can feel overwhelming so here's how I prepare for one.
robertkaplinsky.com/prepare...
robertkaplinsky.com/prepare...
Does a dual flush toilet actually save water versus a single flush toilet? It actually depends on your ratio of "liquids" and "solids" and is a hilarious basis for developing conceptual understanding of systems of equations via tables of values.
robertkaplinsky.com/work/to...
robertkaplinsky.com/work/to...
November 17, 2025 at 12:13 AM
Does a dual flush toilet actually save water versus a single flush toilet? It actually depends on your ratio of "liquids" and "solids" and is a hilarious basis for developing conceptual understanding of systems of equations via tables of values.
robertkaplinsky.com/work/to...
robertkaplinsky.com/work/to...
Read how Spanish teacher Sherry Nesbitt uses #ObserveMe, how she has grown as an educator, and what she has learned along the way.
robertkaplinsky.com/observe...
robertkaplinsky.com/observe...
November 16, 2025 at 1:13 AM
Read how Spanish teacher Sherry Nesbitt uses #ObserveMe, how she has grown as an educator, and what she has learned along the way.
robertkaplinsky.com/observe...
robertkaplinsky.com/observe...
Looking for some free, short growth mindset videos you can show your students? Check out these videos from ClassDojo: ideas.classdojo.com/b/growt...
November 15, 2025 at 8:07 PM
Looking for some free, short growth mindset videos you can show your students? Check out these videos from ClassDojo: ideas.classdojo.com/b/growt...
Do you present to other educators or aspire to? I created a webinar where I go through my entire presentation creation process from start to finish.
For example, I use this three circle Venn diagram to help me choose a topic.
Watch it here: https://info.robertkaplinsky.com/captivating/
For example, I use this three circle Venn diagram to help me choose a topic.
Watch it here: https://info.robertkaplinsky.com/captivating/
November 15, 2025 at 5:45 PM
Do you present to other educators or aspire to? I created a webinar where I go through my entire presentation creation process from start to finish.
For example, I use this three circle Venn diagram to help me choose a topic.
Watch it here: https://info.robertkaplinsky.com/captivating/
For example, I use this three circle Venn diagram to help me choose a topic.
Watch it here: https://info.robertkaplinsky.com/captivating/
If your students are learning about perpendicular lines, try out this Open Middle problem from Andy Schwen with them: www.openmiddle.com/perpendi...
November 14, 2025 at 11:43 PM
If your students are learning about perpendicular lines, try out this Open Middle problem from Andy Schwen with them: www.openmiddle.com/perpendi...
How do you figure out which giant pizza is a better deal? Students will need precision for this lesson which involves areas of circles and rectangles.
robertkaplinsky.com/work/be...
robertkaplinsky.com/work/be...
November 14, 2025 at 8:07 PM
How do you figure out which giant pizza is a better deal? Students will need precision for this lesson which involves areas of circles and rectangles.
robertkaplinsky.com/work/be...
robertkaplinsky.com/work/be...
Are you applying to speak at an upcoming NCTM conference? Then check out these tips to get your proposal accepted.
robertkaplinsky.com/need-kn...
robertkaplinsky.com/need-kn...
November 13, 2025 at 11:34 PM
Are you applying to speak at an upcoming NCTM conference? Then check out these tips to get your proposal accepted.
robertkaplinsky.com/need-kn...
robertkaplinsky.com/need-kn...
If your high school students are working on adding vectors, try out this Open Middle problem from Bryan Anderson. www.openmiddle.com/adding-v...
November 13, 2025 at 1:10 AM
If your high school students are working on adding vectors, try out this Open Middle problem from Bryan Anderson. www.openmiddle.com/adding-v...
Teaching the Pythagorean Theorem? In the Wizard of Oz, the Scarecrow shows off his brains by saying something that was supposed to sound like the Pythagorean Theorem. He was wrong in a few ways so ask students for suggestions to improve what he said.
robertkaplinsky.com/work/wi...
robertkaplinsky.com/work/wi...
November 12, 2025 at 11:14 PM
Teaching the Pythagorean Theorem? In the Wizard of Oz, the Scarecrow shows off his brains by saying something that was supposed to sound like the Pythagorean Theorem. He was wrong in a few ways so ask students for suggestions to improve what he said.
robertkaplinsky.com/work/wi...
robertkaplinsky.com/work/wi...
Here's a matrix multiplication problem from Bryan Anderson that will help you bring out their conceptual understanding. See hints and answers on Open Middle. www.openmiddle.com/matrix-m...
November 10, 2025 at 11:33 PM
Here's a matrix multiplication problem from Bryan Anderson that will help you bring out their conceptual understanding. See hints and answers on Open Middle. www.openmiddle.com/matrix-m...
Do your students ever get frustrated when you don't help them as much as they'd like? Here's what I tell them to appreciate what I'm doing for them.
robertkaplinsky.com/one-way...
robertkaplinsky.com/one-way...
November 10, 2025 at 5:03 PM
Do your students ever get frustrated when you don't help them as much as they'd like? Here's what I tell them to appreciate what I'm doing for them.
robertkaplinsky.com/one-way...
robertkaplinsky.com/one-way...