Tangram Polygons: Composing and Decomposing

In my last post, Tangrams: A World of Geometry, Part Two, I talked about the thirteen convex polygon shapes that can be formed with the seven tangram pieces. In the video, I showed how to make five of them, and then I left a challenge for you to look for the remaining eight convex shapes.… Continue Reading

Total Count-Ability

Total Count-Ability

How many different answers can you find and justify for the nursery rhyme Going to St. Ives? As I was going to St. Ives I met a man with seven wives. Every wife had seven sacks, Every sack had seven cats, Every cat had seven kits. Kits, cats, sacks and wives, How many were going… Continue Reading

Have You Done a Good Math Problem Lately?

Have You Done a Good Math Problem Lately?

In work or social settings it is common to hear the question, “Have you read a good book lately?” The question often starts a lively sharing session about books that elicit pleasure, profundity, or insight. A population that regularly engages in these discussions is an indicator of a literate society. As those appointed by society… Continue Reading

Cab Conundrum

Cab Conundrum

This week’s puzzle is a modification of a brain teaser that has been around for many years—the hotel problem. In the original version of the mathematical paradox, three men pay ten dollars each for a thirty dollar hotel room. Later, they receive a five dollar refund. Because they cannot easily split the five dollars, they each… Continue Reading

Writing a Multiplication Word Problem

Writing a Multiplication Word Problem

Word problems are typically not students’ or teachers’ favorite part of the math lesson. When I talk with teachers, they are frustrated with teaching multiplication word problems. I think one of the things we have been missing is teaching students the structure of what is involved in any multiplication word problem. “Look for and make… Continue Reading

Penny Penning Puzzle

Penny Penning Puzzle

This week’s puzzle is a good one to use early in the school year. It is fairly easy and shouldn’t frustrate students too much in their early exposure to the puzzle-solving process. To do this puzzle, students need only the student sheet depicting the nine-penny arrays and a pencil. The puzzle challenges students to draw… Continue Reading

Partitioning Shapes: Is it Geometry or Fractions?

Partitioning Shapes: Is it Geometry or Fractions?

How early should we teach words like half, thirds, and fourths to children? I know that I have often heard that we give young children things they are not developmentally ready for, and I agree. But when it comes to having language identify a concrete experience, I think children can handle it. I was measuring… Continue Reading

Family Ties

Family Ties

This weeks’s Puzzle Corner activity is a collection of three riddles all dealing with the relationships between relatives. The first one is thought to be many hundreds of years old and is one of the best known brainteasers of all time. I have chosen to leave it in its original form, even though the style of English… Continue Reading

Matching Marbles

Matching Marbles

This activity fits in a category normally called logic problems. Logic problems usually don’t require calculations of any sort, making them different from most other math problems. To solve these types of problems, logical or mathematical thinking must be used. Matching Marbles is a perfect example of this type of problem because to solve it, students must… Continue Reading

Three Great Multiplication Posts

Three Great Multiplication Posts

How to Equip Your Students to Better Understand Multiplication, Part One As I have coached and taught in the classroom, the three most popular ways to describe multiplication is showing ______ groups of ______, using repeated addition and making arrays. Now all of these methods have their place in a student’s understanding of multiplication, but… Continue Reading