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 radical equations? This Open Middle problem from Jonathan Newman will challenge their understandings! www.openmiddle.com/radical-...
December 8, 2025 at 11:33 PM
Are your students working on radical equations? This Open Middle problem from Jonathan Newman will challenge their understandings! www.openmiddle.com/radical-...
Here's my Depth of Knowledge Matrix for middle and high school math from 6th grade to Calculus. Download a PDF version of it to print/share.
robertkaplinsky.com/depth-k...
robertkaplinsky.com/depth-k...
December 8, 2025 at 5:03 PM
Here's my Depth of Knowledge Matrix for middle and high school math from 6th grade to Calculus. Download a PDF version of it to print/share.
robertkaplinsky.com/depth-k...
robertkaplinsky.com/depth-k...
This lesson is a real-life context for transformations including rotations, reflections, and translations. It lets your students initially describe the movements in their own words and then guide them towards a mathematically precise definition.
robertkaplinsky.com/work/ms...
robertkaplinsky.com/work/ms...
December 8, 2025 at 12:13 AM
This lesson is a real-life context for transformations including rotations, reflections, and translations. It lets your students initially describe the movements in their own words and then guide them towards a mathematically precise definition.
robertkaplinsky.com/work/ms...
robertkaplinsky.com/work/ms...
Reposted by Robert Kaplinsky
Heard about Open Middle problems but not sure how to get started? This workshop will get you confident and ready to use them with your students.
Learn more about Robert Kaplinsky's @robertkaplinsky.com How To Use An Open Middle Problem online workshop at grassrootsworkshops.com/wor...
Learn more about Robert Kaplinsky's @robertkaplinsky.com How To Use An Open Middle Problem online workshop at grassrootsworkshops.com/wor...
December 7, 2025 at 7:41 PM
Heard about Open Middle problems but not sure how to get started? This workshop will get you confident and ready to use them with your students.
Learn more about Robert Kaplinsky's @robertkaplinsky.com How To Use An Open Middle Problem online workshop at grassrootsworkshops.com/wor...
Learn more about Robert Kaplinsky's @robertkaplinsky.com How To Use An Open Middle Problem online workshop at grassrootsworkshops.com/wor...
Here are six books that have had a huge impact on me personally and professionally. Let me know which ones would have made your list or I should read next.
robertkaplinsky.com/6-non-e...
robertkaplinsky.com/6-non-e...
December 7, 2025 at 1:13 AM
Here are six books that have had a huge impact on me personally and professionally. Let me know which ones would have made your list or I should read next.
robertkaplinsky.com/6-non-e...
robertkaplinsky.com/6-non-e...
Check out fractiontalks.com/ from Nat Banting for fun images that get students reasoning about fractions. They're all free and ready for you to use.
December 6, 2025 at 8:07 PM
Check out fractiontalks.com/ from Nat Banting for fun images that get students reasoning about fractions. They're all free and ready for you to use.
It's frustrating to find students' hidden misconceptions when it's too late to do anything about them. So check out my free webinar called Three Engaging Methods To Uncover And Fix Hidden Student Misconceptions for tips on what we can do.
Watch here: https://info.robertkaplinsky.com/threemethods
Watch here: https://info.robertkaplinsky.com/threemethods
December 6, 2025 at 5:45 PM
It's frustrating to find students' hidden misconceptions when it's too late to do anything about them. So check out my free webinar called Three Engaging Methods To Uncover And Fix Hidden Student Misconceptions for tips on what we can do.
Watch here: https://info.robertkaplinsky.com/threemethods
Watch here: https://info.robertkaplinsky.com/threemethods
How deeply do your students understand parallel and perpendicular lines if they can't create sets of points to define the lines? Try out these two Open Middle problems from Nanette Johnson:
www.openmiddle.com/perpendi...
www.openmiddle.com/parallel...
www.openmiddle.com/perpendi...
www.openmiddle.com/parallel...
December 5, 2025 at 11:43 PM
How deeply do your students understand parallel and perpendicular lines if they can't create sets of points to define the lines? Try out these two Open Middle problems from Nanette Johnson:
www.openmiddle.com/perpendi...
www.openmiddle.com/parallel...
www.openmiddle.com/perpendi...
www.openmiddle.com/parallel...
How do people determine which product is the best value for your money? Is a coupon always worth using? This lesson will give you a context for talking about the importance of unit rates (and not just price) with your students.
robertkaplinsky.com/work/ca...
robertkaplinsky.com/work/ca...
December 5, 2025 at 8:07 PM
How do people determine which product is the best value for your money? Is a coupon always worth using? This lesson will give you a context for talking about the importance of unit rates (and not just price) with your students.
robertkaplinsky.com/work/ca...
robertkaplinsky.com/work/ca...
Interested in challenging your students with higher Depth of Knowledge problems? Then you'll enjoy my reflection on a 3-step process I often use to create @openmiddle.com problems.
robertkaplinsky.com/create-...
robertkaplinsky.com/create-...
December 4, 2025 at 11:34 PM
Interested in challenging your students with higher Depth of Knowledge problems? Then you'll enjoy my reflection on a 3-step process I often use to create @openmiddle.com problems.
robertkaplinsky.com/create-...
robertkaplinsky.com/create-...
Are your students learning about parallel lines and transversals? Try out these two Open Middle problems from Shelli Foust:
www.openmiddle.com/parallel...
www.openmiddle.com/parallel...
www.openmiddle.com/parallel...
www.openmiddle.com/parallel...
December 4, 2025 at 1:10 AM
Are your students learning about parallel lines and transversals? Try out these two Open Middle problems from Shelli Foust:
www.openmiddle.com/parallel...
www.openmiddle.com/parallel...
www.openmiddle.com/parallel...
www.openmiddle.com/parallel...
How many gumballs fit in the gumball machine? This context for finding the volume of a sphere is also a good opportunity to discuss the difference between inches, square inches, cubic inches, and gumballs as units.
robertkaplinsky.com/work/gu...
robertkaplinsky.com/work/gu...
December 3, 2025 at 11:14 PM
How many gumballs fit in the gumball machine? This context for finding the volume of a sphere is also a good opportunity to discuss the difference between inches, square inches, cubic inches, and gumballs as units.
robertkaplinsky.com/work/gu...
robertkaplinsky.com/work/gu...
This is one of the most adorable thank you cards I've ever received. It comes from Ms. Lemos' students who are big fans of @openmiddle.com. I'm so honored by such a thoughtful gesture.
December 2, 2025 at 7:58 PM
This is one of the most adorable thank you cards I've ever received. It comes from Ms. Lemos' students who are big fans of @openmiddle.com. I'm so honored by such a thoughtful gesture.
Want to challenge your Geometry students to find the area of triangles? Try out this Open Middle problem from Dan Wulf. www.openmiddle.com/area-of-...
December 1, 2025 at 11:33 PM
Want to challenge your Geometry students to find the area of triangles? Try out this Open Middle problem from Dan Wulf. www.openmiddle.com/area-of-...
Some times of the year are better for starting a new initiative and some are a lot worse. Do you know how to find and take advantage of them?
robertkaplinsky.com/behavio...
robertkaplinsky.com/behavio...
December 1, 2025 at 5:03 PM
Some times of the year are better for starting a new initiative and some are a lot worse. Do you know how to find and take advantage of them?
robertkaplinsky.com/behavio...
robertkaplinsky.com/behavio...
While Bed Bath & Beyond stores are no longer around, their coupons provide a context to use. Which should you use to save the most money? The $5 off or 20%? This lesson will help your students figure it out.
robertkaplinsky.com/work/be...
robertkaplinsky.com/work/be...
December 1, 2025 at 12:13 AM
While Bed Bath & Beyond stores are no longer around, their coupons provide a context to use. Which should you use to save the most money? The $5 off or 20%? This lesson will help your students figure it out.
robertkaplinsky.com/work/be...
robertkaplinsky.com/work/be...
Here's the fourth #ObserveMe interview! Bill Wietman, an assistant principal in North Dakota, shares his experiences. robertkaplinsky.com/observe...
November 30, 2025 at 1:13 AM
Here's the fourth #ObserveMe interview! Bill Wietman, an assistant principal in North Dakota, shares his experiences. robertkaplinsky.com/observe...
If you provide professional development to teachers, you have to watch Simon Sinek's TED talk on the importance of WHY. It has been a game changer for me.
www.ted.com/talks/simon_sin...
www.ted.com/talks/simon_sin...
November 29, 2025 at 8:07 PM
If you provide professional development to teachers, you have to watch Simon Sinek's TED talk on the importance of WHY. It has been a game changer for me.
www.ted.com/talks/simon_sin...
www.ted.com/talks/simon_sin...
If you're looking for high quality online professional development that works around your schedule, check out Grassroots Workshops. You'll find lots of options from education leaders you know, like, and trust. You can earn graduate PD credits too!
grassrootsworkshops.com/
grassrootsworkshops.com/
November 29, 2025 at 5:45 PM
If you're looking for high quality online professional development that works around your schedule, check out Grassroots Workshops. You'll find lots of options from education leaders you know, like, and trust. You can earn graduate PD credits too!
grassrootsworkshops.com/
grassrootsworkshops.com/
Here's a challenging Open Middle problem to help students develop conceptual understanding of quadratics in standard form: www.openmiddle.com/maximum-...
November 28, 2025 at 11:43 PM
Here's a challenging Open Middle problem to help students develop conceptual understanding of quadratics in standard form: www.openmiddle.com/maximum-...
A traffic enforcement plane looking for speeding vehicles noticed a motorcycle going exceptionally fast and made some calculations based on distance and time to find the rider's speed. How can we verify if the officer's calculations were correct?
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
November 28, 2025 at 8:07 PM
A traffic enforcement plane looking for speeding vehicles noticed a motorcycle going exceptionally fast and made some calculations based on distance and time to find the rider's speed. How can we verify if the officer's calculations were correct?
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
We're often more attached to the things we already have than to new things that could make our lives even better. This makes it difficult to replace old ideas with new ones in math education.
Read more: robertkaplinsky.com/behavio...
Read more: robertkaplinsky.com/behavio...
November 27, 2025 at 11:34 PM
We're often more attached to the things we already have than to new things that could make our lives even better. This makes it difficult to replace old ideas with new ones in math education.
Read more: robertkaplinsky.com/behavio...
Read more: robertkaplinsky.com/behavio...
If your Geometry students are working on the midpoint formula, try out this Open Middle problem from Dane Ehlert with them. www.openmiddle.com/midpoint...
November 27, 2025 at 1:10 AM
If your Geometry students are working on the midpoint formula, try out this Open Middle problem from Dane Ehlert with them. www.openmiddle.com/midpoint...
NFL cornerback Patrick Peterson received a $15,361,000 signing bonus but didn't cash the check for almost a month. When asked why, he said, “I just haven’t gotten around to it.” He could have bought a car with the interest he lost!
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
November 26, 2025 at 11:14 PM
NFL cornerback Patrick Peterson received a $15,361,000 signing bonus but didn't cash the check for almost a month. When asked why, he said, “I just haven’t gotten around to it.” He could have bought a car with the interest he lost!
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
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...