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 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...
This lesson requires students to integrate multiple skills including reading and interpreting maps, understanding that distance is always positive (absolute value), and placing fractions on a number line.
robertkaplinsky.com/work/wh...
robertkaplinsky.com/work/wh...
November 10, 2025 at 12:13 AM
This lesson requires students to integrate multiple skills including reading and interpreting maps, understanding that distance is always positive (absolute value), and placing fractions on a number line.
robertkaplinsky.com/work/wh...
robertkaplinsky.com/work/wh...
Looking for an example of what the Common Core's coherence shift looks like? Here's how real-world example of how geometry grows from kindergarten through high school.
robertkaplinsky.com/what-do...
robertkaplinsky.com/what-do...
November 9, 2025 at 1:13 AM
Looking for an example of what the Common Core's coherence shift looks like? Here's how real-world example of how geometry grows from kindergarten through high school.
robertkaplinsky.com/what-do...
robertkaplinsky.com/what-do...
If you wish you had questions you could ask your students to encourage them to use their intuition, then check out this ready to go list from Tracy Zager: tjzager.com/wp-content/uplo...
You can get her book here: amzn.to/4eSBiMY
You can get her book here: amzn.to/4eSBiMY
November 8, 2025 at 8:07 PM
If you wish you had questions you could ask your students to encourage them to use their intuition, then check out this ready to go list from Tracy Zager: tjzager.com/wp-content/uplo...
You can get her book here: amzn.to/4eSBiMY
You can get her book here: amzn.to/4eSBiMY
If you teach others through online workshops, then you should check out my webinar recording on 6 counterintuitive lessons learned I wish I had understood earlier. For example, should workshops feel more like watching Netflix or traditional TV?
robertkaplinsky.com/pdwebinar
robertkaplinsky.com/pdwebinar
November 8, 2025 at 5:45 PM
If you teach others through online workshops, then you should check out my webinar recording on 6 counterintuitive lessons learned I wish I had understood earlier. For example, should workshops feel more like watching Netflix or traditional TV?
robertkaplinsky.com/pdwebinar
robertkaplinsky.com/pdwebinar
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...
November 7, 2025 at 11:43 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...
NASA stopped painting its space shuttles’ external fuel tank because the paint did not improve performance and they wanted to reduce the shuttle’s overall weight. Would you believe the paint had weighed 600 lb when dry?!?
robertkaplinsky.com/work/fu...
robertkaplinsky.com/work/fu...
November 7, 2025 at 8:07 PM
NASA stopped painting its space shuttles’ external fuel tank because the paint did not improve performance and they wanted to reduce the shuttle’s overall weight. Would you believe the paint had weighed 600 lb when dry?!?
robertkaplinsky.com/work/fu...
robertkaplinsky.com/work/fu...
Here's my interview with Nate Bowling on how implementing #ObserveMe in his classroom has helped him grow.
robertkaplinsky.com/observe...
robertkaplinsky.com/observe...
November 6, 2025 at 11:34 PM
Here's my interview with Nate Bowling on how implementing #ObserveMe in his classroom has helped him grow.
robertkaplinsky.com/observe...
robertkaplinsky.com/observe...
Are your students working on radical equations? This Open Middle problem from Jonathan Newman will challenge their understandings! www.openmiddle.com/radical-...
November 6, 2025 at 1:10 AM
Are your students working on radical equations? This Open Middle problem from Jonathan Newman will challenge their understandings! www.openmiddle.com/radical-...
Coke Freestyle machines allow you to take soft drinks and add up to 14 flavors to them. What strategies might your students use to determine how many soda combinations there are on a Coca-Cola Freestyle?
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
November 5, 2025 at 11:14 PM
Coke Freestyle machines allow you to take soft drinks and add up to 14 flavors to them. What strategies might your students use to determine how many soda combinations there are on a Coca-Cola Freestyle?
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
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...
November 3, 2025 at 11:33 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...
Power and influence look similar, but their differences matter. I break them down in this 10-minute presentation that's my favorite talk I've ever given.
robertkaplinsky.com/my-shad...
robertkaplinsky.com/my-shad...
November 3, 2025 at 5:03 PM
Power and influence look similar, but their differences matter. I break them down in this 10-minute presentation that's my favorite talk I've ever given.
robertkaplinsky.com/my-shad...
robertkaplinsky.com/my-shad...
Many theme parks offer season passes where you can pay for the whole year in advance or make monthly payments. Try this math lesson to determine which method is cheaper. And your students will learn about decimal operations along the way!
robertkaplinsky.com/work/mo...
robertkaplinsky.com/work/mo...
November 3, 2025 at 12:13 AM
Many theme parks offer season passes where you can pay for the whole year in advance or make monthly payments. Try this math lesson to determine which method is cheaper. And your students will learn about decimal operations along the way!
robertkaplinsky.com/work/mo...
robertkaplinsky.com/work/mo...
Want the Common Core Standards for Mathematical Practice in Arabic, Armenian, Chinese, Korean, Spanish, or Tagalog?
Download PDFs here: robertkaplinsky.com/standar...
Download PDFs here: robertkaplinsky.com/standar...
November 2, 2025 at 12:13 AM
Want the Common Core Standards for Mathematical Practice in Arabic, Armenian, Chinese, Korean, Spanish, or Tagalog?
Download PDFs here: robertkaplinsky.com/standar...
Download PDFs here: robertkaplinsky.com/standar...
If you have a website (or are planning on making one), you should check out my webinar on three things your website should include and one you should avoid.
The examples are specific to educational consulting, but apply to all websites.
info.robertkaplinsky.com/we...
The examples are specific to educational consulting, but apply to all websites.
info.robertkaplinsky.com/we...
November 1, 2025 at 4:45 PM
If you have a website (or are planning on making one), you should check out my webinar on three things your website should include and one you should avoid.
The examples are specific to educational consulting, but apply to all websites.
info.robertkaplinsky.com/we...
The examples are specific to educational consulting, but apply to all websites.
info.robertkaplinsky.com/we...
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...
October 31, 2025 at 10:43 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...
This lesson uses a time lapse thermometer video as a context for discussing integer operations and absolute value. The video should provide some added meaning to the classic temperature drop problem.
robertkaplinsky.com/work/te...
robertkaplinsky.com/work/te...
October 31, 2025 at 7:07 PM
This lesson uses a time lapse thermometer video as a context for discussing integer operations and absolute value. The video should provide some added meaning to the classic temperature drop problem.
robertkaplinsky.com/work/te...
robertkaplinsky.com/work/te...
It's so frustrating when students mix up area and perimeter. Here's my take on why it happens and what we can do about it.
robertkaplinsky.com/student...
robertkaplinsky.com/student...
October 30, 2025 at 10:34 PM
It's so frustrating when students mix up area and perimeter. Here's my take on why it happens and what we can do about it.
robertkaplinsky.com/student...
robertkaplinsky.com/student...
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-...
October 30, 2025 at 12:10 AM
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-...
This lesson is a real world context for dividing fractions and mixed numbers that has many opportunities for students to show you their misconceptions about dividing fractions.
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
October 29, 2025 at 10:14 PM
This lesson is a real world context for dividing fractions and mixed numbers that has many opportunities for students to show you their misconceptions about dividing fractions.
robertkaplinsky.com/work/ho...
robertkaplinsky.com/work/ho...
Here's a challenging Open Middle problem to help students develop conceptual understanding of quadratics in standard form: www.openmiddle.com/maximum-...
October 27, 2025 at 10:33 PM
Here's a challenging Open Middle problem to help students develop conceptual understanding of quadratics in standard form: www.openmiddle.com/maximum-...
Sometimes people look at @openmiddle.com problems and dismiss them as just brainteasers and not worth using. Here's my take.
robertkaplinsky.com/higher-...
robertkaplinsky.com/higher-...
October 27, 2025 at 4:03 PM
Sometimes people look at @openmiddle.com problems and dismiss them as just brainteasers and not worth using. Here's my take.
robertkaplinsky.com/higher-...
robertkaplinsky.com/higher-...