Author Archives: Richard Thiessen

Do Comics Have a Place in Your Classroom?

One feature of the AIMS Essential Math Units, a series that is targeted for middle school, is the inclusion of comics as a way to show students engaged with some of the activities in a unit. Our hope for the comics was that they would help to make explicit the content knowledge that is the… Continue Reading

Five Squares, One Square: Solution

In two previous blog posts I talked about a puzzle made up of five two by two squares, where each square was cut in two along a line from a vertex to the midpoint of a side. The challenge, which I gave in the first post, was to put the ten pieces together to form… Continue Reading

What Does Twice as Big Mean?

I’m often puzzled by the way we use phrases like twice as big. What does that mean? For example, I understand that if my debt 5 years ago was \$10,000 and today it’s \$20,000, then my debt is twice as big today as it was 5 years ago. I also understand that if one two-by-four… Continue Reading

Taking Apart and Putting Together Cubes

In earlier posts I’ve mentioned Friedrich Froebel and his geometric gifts. The third of his geometric gifts was a box containing eight cubes. Instead of the students simply opening the lid and dumping the cubes on the table, he would have the students place the box with the lid down on the table, slide the… Continue Reading

Five Squares, One Square: Some Hints and an Extension

In an earlier blog post I proposed a puzzle made of five 2 by 2 squares, each of which had been cut along a line from a corner to the midpoint of an opposite side so as to form a right triangle and a trapezoid with two right angles. The challenge of the puzzle was… Continue Reading

One Object Three Shapes: The Solution

In an earlier post, One Object Three Shapes, we posed the problem of finding an object that would appear to be a triangle when viewed in one way, a square when viewed in another way, and a circle when viewed in yet a third way. The challenge was to create an object that would fit… Continue Reading

Five Squares, One Square

A while back I posted a five triangle puzzle that involved putting together five 30-60-90 triangles to form a single triangle. Of all of the dozens of puzzles that I own and have made over the years, that is one of my favorites because of the opportunities it provides for students to think about important… Continue Reading

The Five Triangle Puzzle: Solutions

The Five Triangle Puzzle was the subject of a post back on February 11. I’m hopeful that some of you will have downloaded the pieces and solved the puzzle. The challenge was to put all five pieces together to form a triangle and then to determine if there were other triangles that could be formed… Continue Reading

One Object Three Shapes: Circle Square Triangle

Front and back, top and bottom, and left and right are ideas that we use to describe objects in our three-dimensional world. Young children learn these positional words in Kindergarten. In fact, learning the meaning of these words is one of the Common Core Kindergarten geometry standards. In reality these are big ideas that are… Continue Reading

Month, Day, Year: A Number Sequence

Daily journaling is one of the constants in my life. Over many years, I don’t believe there has been a single day when I did not make at least half a dozen entries in my journal. Each entry is dated, so on any given day I will write the date at least half a dozen… Continue Reading