7 and 8 years old

Seven and eight-year-olds are making arguments. They’ll tell you something is true, and why it has to be true. More and more, they see math in the world, and they want to tell you about it.

A sign on a light pole reads "Como Lake. 1.6 miles - 3200 steps around the lake"
A walk around the lake

A walk around the lake

A very snowy winter is turning to a long, slow spring here in Minnesota. It is the kind of spring that makes us joyful for sunny 45° days. So I went for a long walk Sunday afternoon. Together with a meaningful percentage of the population of the city of Saint Paul,...

A rectangle made of 12 teal-colored kites, four pink right triangles, and four blue diamonds in an arrangement that has both horizontal and vertical lines of symmetry.
A 21st Century Challenge

A 21st Century Challenge

After seeing Hana Murray's lovely study of rectangles made from 21st Century Pattern Blocks, I started playing and noticed that many of them seemed to involve the small green triangles. Pretty soon, I had formed a conjecture. Using copies of these at least two...

Tabitha holding a large onion
Weighing onions

Weighing onions

I have had several conversations with relatively new parents in which the question of how/whether to talk math with babies. I always try to help such parents see math like they see reading. You read with your baby long before she knows what your words mean. An...