Select Page

“Is 100 a Teen Number?” Part 2

What follows is a lightly edited version of the second part of an end-of-Kindergarten discussion about the teen numbers. In Part 1, students took up the question of whether 100 is a teen number. That conversation built on a previous one, about why there are so many 1s...

“Is 100 a Teen Number?” Part 1

Not long after I witnessed a Kindergarten conversation about why there are so many 1s in the teen numbers, I visited the same classroom. This time, it was Nicole who asked a question that knocked my socks off. “I wonder if 100 is a teen number?” When I asked why she...

Are There Going to Be More Than 20? More Than 50?

Many of us were taught to “estimate” in elementary school. Maybe we were asked how many jellybeans there were in a jar. Or asked to round before finding the answer to a computation problem. But for many of us there was little connection between those activities and...

“Why are there so much 1s in these numbers?”

Last spring, I visited a Kindergarten classroom near the end of the year. Students were participating in a Math Workshop focused on the teen numbers, choosing among activities that asked them to identify and recognize teen numbers; to represent them in several...

When the Math Is What’s Exciting

I’ve been really lucky to spend time in a grade 1 classroom this spring, as they tackle the final number unit of the year. 1U7 is the culmination of students’ work with addition, subtraction, and place value. Building on the work of the earlier number units, it...

“This is Only Getting Better!…And Harder!”

Who knew a deck of +10/-10 cards could be so exciting? A group of 25 first graders, that’s who. As their teacher, Karla, introduced them to Plus or Minus 10, she explained that they would need numeral cards (10-90), cubes (assembled in sticks of ten), and a new deck...

The Hard Work of Counting by Groups, Part 2

Last week, I wrote about some first graders’ work on problems about how many fingers were on 4 or 8 hands. This week, I want to share an interaction I had with one child, as the class’s work turned to thinking about groups of 10. Students were working on two types of...