Category Archives: Math 8

Euclid’s Algorithm

I show my 6th graders this image, pointing out that this picture represents the two numbers 1 and 1 that I’d entered at the top. I then ask them to give me two new numbers — any two positive integers [that are 10 or less, for now] — and the computer will draw a new […]

Also posted in Course 1 (6th Grade Math), Problem Solving | Tagged , , , , , , , , | 7 Responses

Solving an Equation with a Fraction

From CPM: The Sutton family took a trip to see the mountains in Rocky Mountain National Park.  Linda and her brother, Lee, kept asking, “Are we there yet?”  At one point, their mother answered, “No, but what I can tell you is that we have driven 100 miles and we are about 2/5 of the way there.” […]

Also posted in Algebra, Course 1 (6th Grade Math) | Tagged , , | 5 Responses

Ethan Hall, teacher and web entrepreneur from Israel, emailed me this morning asking me to check out his visual patterns generator on There’s a lot of cool graphing tools other than the VP generator. I’m kinda blown away. Go play! Go do math!

Also posted in Algebra, Course 1 (6th Grade Math), General, Geometry, Problem Solving | Tagged , , | 5 Responses

Joint Investment

Would you have known immediately that the number 1729 is the sum of two cubes? You think you’re so smart, but you’re no Ramanujan. He told Hardy that 1729 is the sum of two cubes in two ways: 13+123 and 93+103. I read The Man Who Knew Infinity a few years ago. I might check out the movie when it hits […]

Also posted in Problem Solving | Tagged , , , , | 1 Response

The Shoe Sale

(On a side note, I’m not sure what I love more, my left foot or Google Classroom.) This problem is from Peter Liljedahl’s site. The Shoe Sale You decide to take advantage of a buy 2 pair get 1 pair of equal or lesser value for free sale at the local shoe store. The problem is […]

Also posted in Course 1 (6th Grade Math) | Tagged , , , , , | 3 Responses

Desmos Puppy House

We don’t cover quadratic in Math 8 this year, so we really can’t do Des-man. I come up with “Puppy House” instead so my students can still create something that allows them lots of practice with writing linear equations with domain and range restrictions. They draft the house on paper. The house needs to have a minimum of 6 […]

Also posted in Algebra | Tagged , , , , , , | 3 Responses

Grade 6 Rocks Visual Patterns

I’m always happy to hear how teachers use with their students. Michael Fenton shares how he uses the patterns with Desmos. And this. Alex Overwijk’s students use the big whiteboards. Whiteboard photos of that my S’s did yesterday….thanks — Alex Overwijk (@AlexOverwijk) March 7, 2015   Bridget Dunbar removes some figures, and […]

Also posted in Algebra, Course 1 (6th Grade Math) | Tagged , , , | 12 Responses

Reversing the Question

Don Steward posted this on Sunday. Like Don, I really like this task and also think it has a certain Malcolm Swan je ne sais quoi about it. I showed only the top part to my 6th graders, and I gave them 2 minutes to write down what they notice. In addition to noticing the given information, the students also mentioned: […]

Also posted in Course 1 (6th Grade Math) | Tagged , , , , , , | 16 Responses


Our black lab Mandy is 3.5 years old, weighs a ton, and her breath used to smell like death. Until we started giving her one Greenies a day. My husband orders them from Amazon, he also gets them for our neighbor’s small dog Bailey. Although both boxes weigh the same 36 ounces, Bailey gets 130 treats in the Teenie size and Mandy […]

Posted in Math 8 | Tagged , , , , , , , , | 5 Responses

Rigid Transformations

My 8th graders are learning about rigid transformations. I want to add a bit more complexity to what our book is asking the kids to do. For example, the book is having them reflect a shape mainly across the x-axis or y-axis, or on a rare occasion, reflect it across “the horizontal line that goes through […]

Also posted in Geometry | Tagged , , , , , , | 8 Responses