Counting in downtown Saint Paul

I had my first book event today—for How Many? at Subtext Books in downtown Saint Paul. Lovely people, great little independent bookstore. You should buy some books from them. We had a small but loyal crowd that included a three-year old and an eight-year old. The three-year old was charming, as all three-year olds are, […]

Does the Earth have an end?

Talking Math with Other People’s Kids Month continues… A while back, Rafranz Davis reported a conversation on her blog. She writes frequently about the adventures she has with her nephew Braeden. I asked, and she gave me permission to remix a conversation she and Braeden had about the ends of shapes—especially the ends of the […]

Doll years

Out of the blue on our recent camping trip, Tabitha had an announcement for me. Tabitha (6 years old): I am 12 in doll years and Griffy is 16 in doll years. Her brother Griffin is 9. T: So how old are you in doll years, Daddy? Me: Well, how do doll years work? T: […]

Cold snap

Tabitha (9 years old) is keenly attuned to the temperatures these days, as subzero air temperatures or wind chills mean indoor recess. Being a child of great physical energy, indoor recess is not ideal. We have an indoor/outdoor thermometer on our kitchen table, which she checks several times a day. Yesterday evening before doing the dishes […]

Cookies under constraints

A propos of nothing one day, I ask Griffin (9 years old at the time, finishing up fourth grade) a question. Me: Griff, imagine you are baking cookies and you need cup of sugar, but you only have a cup measure. How would you get  cup? He thinks about this for a moment. Griffin (9 years […]


This is one of my favorite tasks in recent years. The idea is that we will compare two sets of Peeps. Are there more of one color or the other? There is so much fun to be had counting Peeps. Now that Valentine’s Day is past, Peeps (a common Easter candy) are back in stores […]


The dirty little secret about Legos is how very many pieces there are to be cleaned up after building. And how very ugly the clean-up battle can become. I try to keep calm. I try to turn the clean-up battle into math talk from time to time. Here is how it played out a while […]

Patterns on the multiplication machine

Tabitha (6 years old) has been playing with the multiplication machine off and on for a few months now. We have never once used it for learning multiplication facts, but we have had a ton of math-learning fun with it. Recently, she carefully did an up-down-up-down pattern that she continued along all of the columns. We […]

The meanings of division

I was talking with Griffin one day when he was in third grade. Me: Do you know what is? Griffin (8 years old): 6 Me: How do you know that’s right? G: 2 times 6 is 12. Me: What about ? G: 13 Me: How do you know that? G: There were 26 kids in Ms. Starr’s class [in first […]