Dear Families,
The Teachers’ Lounge is a problem that pushes students to think deeply and carefully about division situations. It highlights the two types of division situations, quotative and partitive, or grouping and sharing.
In a quotative, or grouping division situation, the number in each group is known and the number of groups is unknown: 24 fourth graders are playing soccer. The coaches want to make teams of 6. How many teams can they make? 6 is the number in each group, and the unknown is how many groups will be made with 24 kids.
In a partitive, or sharing division situation, the number of groups is known and the number in each group is unknown: I have 24 cookies to share with 6 friends. How many cookies can I give to each friend? 6 is the number of groups, and the unknown is how many cookies will be in each group.
In the classroom, we talk about whether a division situation is asking “How many groups?” or “How many in each group?” When you look at the student work below, that is one place your conversation might go. When you read the juice and water machine situations, think about which problem is a quotative situation and which problem is a partitive situation.
Please start by reading the problem, and involve your child in viewing his or her work. You'll find some questions below that will guide your conversation.
Please bear in mind that each pair of students saw these problems differently and therefore solved them differently. Each partnership’s work is valid. There was no “right way” to go about this.
We started working on this problem last week. Working with their math partners, students solved the problem and showed their thinking on a poster using equations, pictures and words. They worked hard to make their work both accurate and clear. Today, math teams switched posters and left notes for each other about what could make the posters better. Revisions were made, and then we had a math meeting on the rug where several students shared their work. After the meeting, each student wrote about how he or she felt The Teachers’ Lounge problem helped them grow as mathematicians (That might be a good way to begin your conversations.).
I love this problem. As I told the class today, it's like a washing machine. They go in grass-stained 3rd grade mathematicians and come out clean and shiny 4th grade mathematicians. This work sets the bar for the level of deep mathematical thinking they'll be doing all year. I hope you are as moved by the sophisticated thinking you'll see in their work as I was.
Happy thinking,
Lauren