I had a collection of five pennies. The dates on them were:

1996

1993

1987

1990

1994

After I added one more penny to my collection, the mean date changed.

]]>On Thanksgiving Thursday, Carissa ate some cranberries. The next day she couldn’t stop thinking about how good the cranberries were and ate seven more cranberries than she had eaten on Thursday.

Each day after that she ate seven more cranberries than the day before. By the following Wednesday night she had eaten a total of 161 cranberries for the whole week.

]]>**What do you notice in the video below? What are you wondering about? Leave a comment to tell us your thoughts!**

Exploring interactive applets that let students “notice and wonder”, talk about mathematical situations, and develop conceptual understandings of triangle properties, linear equations, systems of equations, and factoring trinomials.

PCTM 63rd Annual Conference, November 2014

Session Handout [PDF]

For more about the Math Forum, including information from our other talks at PCTM 2014, visit our conference page at http://mathforum.org/workshops/pctm2014/.

**Types of Triangles** – Annie Fetter

Link above includes handouts, sketch, and Sketch Explorer version

*Key technology strengths: exploring dynamic models of different triangle types, allowing students to develop intuition about different classes of triangles and what characteristics they do and don’t have.*

**Runners** – NCTM e-Examples from Principles and Standards

*Key technology strengths: developing intuition about distance/rate/time and the concept of slope, without needing to know the formal vocabulary at all, as well as the ability to try things and get it wrong, and get instant feedback without fear of judgement by others.*

**Galactic Exchange** – The Math Forum’s ESCOT Project

Galactic Exchange Handouts (PDF)

*Key technology strengths: the applet does the recordkeeping for you, and students can explore systems of equations without needing to know that they’re doing that, or even knowing that such a thing exists!*

**Algebra Tiles** – National Library of Virtual Manipulatives

*Key technology strengths: the variables actually vary!*

What do you notice in the story below? What are you wondering about? Leave a comment to tell us your thoughts!

A square is drawn on a coordinate plane. The square is in the first quadrant and the sides of the square are parallel to the axis.

]]>A line is drawn from the origin that cuts the square into two sections whose areas are in a ratio of 2:1.

What do you notice in the story below? What are you wondering about? Leave a comment to tell us your thoughts!

]]>What do you notice in the story below? What are you wondering about? Leave a comment to tell us your thoughts!

A circus clown has 16 balloons. One half of the balloons are red. Half of the remaining balloons are blue. The rest are yellow.

Annie Fetter, The Math Forum @ Drexel University, Philadelphia, PA

Session 12 Handout [pdf]

**How This All Started – Formative Assessment
**

- Constructing Quadrilaterals Activity (see handout)
- Making Movies Using Jing – Instructions [PDF]
- Kathy’s Movie
- Danielle’s Movie

**Where it Went from There – Summative Assessment
**

- Red Shirt’s Movie
- Christina’s Rubric (see handout)

**Then Debbie Got Involved**

Annie is the Problem of the Week Coordinator and Professional Development Specialist at the Math Forum. She also teaches three courses in Drexel’s Math Learning and Teaching Masters program,

Every Friday night, Drew’s family makes pizza for dinner. This week, Drew wants pepperoni and his sister wants extra cheese. His parents both want mushrooms as a topping.

Since they couldn’t agree, they decided to divide the pizza into four equal parts so everyone could have the topping of their choice.