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
If your students are learning about perpendicular lines, try out this Open Middle problem from Andy Schwen with them: www.openmiddle.com/perpendi...
January 26, 2026 at 11:33 PM
If your students are learning about perpendicular lines, try out this Open Middle problem from Andy Schwen with them: www.openmiddle.com/perpendi...
Is it scary or dangerous for teachers to try new techniques in their classroom? Do they mean the same thing???
What about using the same teaching methods for an entire career? Learn more about the differences between scary and dangerous.
robertkaplinsky.com/differe...
What about using the same teaching methods for an entire career? Learn more about the differences between scary and dangerous.
robertkaplinsky.com/differe...
January 26, 2026 at 5:03 PM
Is it scary or dangerous for teachers to try new techniques in their classroom? Do they mean the same thing???
What about using the same teaching methods for an entire career? Learn more about the differences between scary and dangerous.
robertkaplinsky.com/differe...
What about using the same teaching methods for an entire career? Learn more about the differences between scary and dangerous.
robertkaplinsky.com/differe...
Have you ever had two coupons you could use and thought about which would benefit you more? Here's a context to put students in a similar situation. When is it better to use the 10% off coupon and when is it better to get a free item?
robertkaplinsky.com/work/ch...
robertkaplinsky.com/work/ch...
January 26, 2026 at 12:13 AM
Have you ever had two coupons you could use and thought about which would benefit you more? Here's a context to put students in a similar situation. When is it better to use the 10% off coupon and when is it better to get a free item?
robertkaplinsky.com/work/ch...
robertkaplinsky.com/work/ch...
SOAP BOX: I'm going to try and convince you that maybe we shouldn't be providing professional development for all teachers.
robertkaplinsky.com/should-...
robertkaplinsky.com/should-...
January 25, 2026 at 1:13 AM
SOAP BOX: I'm going to try and convince you that maybe we shouldn't be providing professional development for all teachers.
robertkaplinsky.com/should-...
robertkaplinsky.com/should-...
Here are some early elementary 3-act tasks from Kendra Lomax. They definitely get kids thinking more deeply about math.
learningfromchildren.org/3-...
learningfromchildren.org/3-...
January 24, 2026 at 8:07 PM
Here are some early elementary 3-act tasks from Kendra Lomax. They definitely get kids thinking more deeply about math.
learningfromchildren.org/3-...
learningfromchildren.org/3-...
If you're a current or aspiring educational consultant that trains other educators and you're looking for a community that gets what you're going through, you should join the over one thousand consultants in our Facebook group here: https://www.facebook.com/groups/edconsultantslab
January 24, 2026 at 5:45 PM
If you're a current or aspiring educational consultant that trains other educators and you're looking for a community that gets what you're going through, you should join the over one thousand consultants in our Facebook group here: https://www.facebook.com/groups/edconsultantslab
If your high school students are working on adding vectors, try out this Open Middle problem from Bryan Anderson. www.openmiddle.com/adding-v...
January 23, 2026 at 11:43 PM
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 least common multiple? Check out this lesson starring Steve Martin in Father of the Bride that uses the context of buying hot dogs and buns as a context for making sense of the mathematics.
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
January 23, 2026 at 8:07 PM
Teaching least common multiple? Check out this lesson starring Steve Martin in Father of the Bride that uses the context of buying hot dogs and buns as a context for making sense of the mathematics.
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
Do you wish you had a way to read your students' minds so you could spot their misconceptions? Even when they don't realize that they have any???
robertkaplinsky.com/van-hal...
robertkaplinsky.com/van-hal...
January 22, 2026 at 11:34 PM
Do you wish you had a way to read your students' minds so you could spot their misconceptions? Even when they don't realize that they have any???
robertkaplinsky.com/van-hal...
robertkaplinsky.com/van-hal...
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...
January 22, 2026 at 1:10 AM
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...
Help your students stay safe online by understanding the math behind password safety. SPOILER: longer passwords are far better than more complex passwords. Now they can better understand why.
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
January 21, 2026 at 11:14 PM
Help your students stay safe online by understanding the math behind password safety. SPOILER: longer passwords are far better than more complex passwords. Now they can better understand why.
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
Algebra teachers, check out these three rational exponent problems from Bryan Anderson. See the hints and answers on Open Middle:
www.openmiddle.com/rational...
www.openmiddle.com/rational...
www.openmiddle.com/rational...
www.openmiddle.com/rational...
www.openmiddle.com/rational...
www.openmiddle.com/rational...
January 19, 2026 at 11:33 PM
Algebra teachers, check out these three rational exponent problems from Bryan Anderson. See the hints and answers on Open Middle:
www.openmiddle.com/rational...
www.openmiddle.com/rational...
www.openmiddle.com/rational...
www.openmiddle.com/rational...
www.openmiddle.com/rational...
www.openmiddle.com/rational...
If you are tired of schools forcing kids to learn multiple years of math in a single year, this is the post for you.
robertkaplinsky.com/the-cas...
robertkaplinsky.com/the-cas...
January 19, 2026 at 5:03 PM
If you are tired of schools forcing kids to learn multiple years of math in a single year, this is the post for you.
robertkaplinsky.com/the-cas...
robertkaplinsky.com/the-cas...
If you're looking for a 6th or 7th grade lesson on rates, proportions, and distance, this Minecraft lesson is perfect for your students
Check it out and download all the videos and images here:
robertkaplinsky.com/work/wh...
Check it out and download all the videos and images here:
robertkaplinsky.com/work/wh...
January 19, 2026 at 12:13 AM
If you're looking for a 6th or 7th grade lesson on rates, proportions, and distance, this Minecraft lesson is perfect for your students
Check it out and download all the videos and images here:
robertkaplinsky.com/work/wh...
Check it out and download all the videos and images here:
robertkaplinsky.com/work/wh...
If you enjoy using my real world problem-based lessons or the problems I share on @openmiddle.com, then you should check out my online workshop where share my favorite tips for using them.
robertkaplinsky.com/eps #epsworkshop
robertkaplinsky.com/eps #epsworkshop
January 18, 2026 at 1:13 AM
If you enjoy using my real world problem-based lessons or the problems I share on @openmiddle.com, then you should check out my online workshop where share my favorite tips for using them.
robertkaplinsky.com/eps #epsworkshop
robertkaplinsky.com/eps #epsworkshop
I love the Number Strings resources broken down by topic that Kara Imm and Rachel Lambert share at numberstrings.com/. Most are for elementary school but they have examples up to Algebra.
January 17, 2026 at 8:07 PM
I love the Number Strings resources broken down by topic that Kara Imm and Rachel Lambert share at numberstrings.com/. Most are for elementary school but they have examples up to Algebra.
If you've also used worksheets to teach your students math, then I've recorded a webinar you'll want to check out. It's called Why We Should Reconsider Using Worksheets (And What We Should Be Doing Instead), with K-5 and 6-12 versions.
robertkaplinsky.com/worksheets
robertkaplinsky.com/worksheets
January 17, 2026 at 5:45 PM
If you've also used worksheets to teach your students math, then I've recorded a webinar you'll want to check out. It's called Why We Should Reconsider Using Worksheets (And What We Should Be Doing Instead), with K-5 and 6-12 versions.
robertkaplinsky.com/worksheets
robertkaplinsky.com/worksheets
I had the opportunity of a lifetime to work in Barcelona, Spain where I taught 6th graders and presented to educators in Spanish about Open Middle. It was even covered in a newspaper! I am so grateful for this amazing opportunity.
January 11, 2026 at 9:51 AM
I had the opportunity of a lifetime to work in Barcelona, Spain where I taught 6th graders and presented to educators in Spanish about Open Middle. It was even covered in a newspaper! I am so grateful for this amazing opportunity.
Reposted by Robert Kaplinsky
Elementary math Ts, here's a tool for your file! 📁
Check out educator
@robertkaplinsky.com's matrix illustrating how cognitive demand shifts within the same content:
robertkaplinsky.com/depth-knowle...
Check out educator
@robertkaplinsky.com's matrix illustrating how cognitive demand shifts within the same content:
robertkaplinsky.com/depth-knowle...
January 7, 2026 at 12:01 PM
Elementary math Ts, here's a tool for your file! 📁
Check out educator
@robertkaplinsky.com's matrix illustrating how cognitive demand shifts within the same content:
robertkaplinsky.com/depth-knowle...
Check out educator
@robertkaplinsky.com's matrix illustrating how cognitive demand shifts within the same content:
robertkaplinsky.com/depth-knowle...
How do you find the area covered by the Bermuda Triangle? This lesson is a great context for Geometry or Integrated II students looking to find the area of triangles on a coordinate plane.
robertkaplinsky.com/work/be...
robertkaplinsky.com/work/be...
January 9, 2026 at 8:07 PM
How do you find the area covered by the Bermuda Triangle? This lesson is a great context for Geometry or Integrated II students looking to find the area of triangles on a coordinate plane.
robertkaplinsky.com/work/be...
robertkaplinsky.com/work/be...
Did you know that many of the stores you shop at use mathematical modeling to make predictions about you? Read about how Target can predict which of its customers are pregnant and when the baby is due!
robertkaplinsky.com/math-mo...
robertkaplinsky.com/math-mo...
January 8, 2026 at 11:34 PM
Did you know that many of the stores you shop at use mathematical modeling to make predictions about you? Read about how Target can predict which of its customers are pregnant and when the baby is due!
robertkaplinsky.com/math-mo...
robertkaplinsky.com/math-mo...
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...
January 8, 2026 at 1:10 AM
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...
Attention high school math teachers! How do you measure distance on a circular road? This lesson provides a context for students to develop conceptual understanding of arc length.
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
January 7, 2026 at 11:14 PM
Attention high school math teachers! How do you measure distance on a circular road? This lesson provides a context for students to develop conceptual understanding of arc length.
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
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...
January 5, 2026 at 11:33 PM
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...
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-...
January 2, 2026 at 11:43 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-...