**Dear Chris Shore,**

Thanks for introducing Tustin Unified to

*Clothesline*during your awesome professional development workshop!

You, Math Projects Journal, and Clothesline rock (

*David Lee Roth style*)!

With all of my math heart,

Andrew

*Check out Chris' post on Clothesline (

*link coming soon*).

**I highly recommend inviting Chris to your district/school for math workshops.

**Where do I begin?**

I used to have a number line in my old class. But it was static. All of the benchmark numbers were taped to the wall. I used it often, but not often enough.

**Flash forward to Chris' workshop last week.**He introduced Clothesline using this great quote from Tim McCaffrey:

```
"Clothesline is the master number sense maker." says @timsmccaffrey according to @MathProjects. Good call Tim! pic.twitter.com/bVvvJz7CtX
— Andrew Stadel (@mr_stadel) August 19, 2015
```

You better believe my ears perked up when I heard "master number sense maker". Check it out!**When I worked with teachers in Irvine today**, my ice breaker was asking the teachers,

"How long does Dyson think it should take you to dry your hands with their machine?"I've never posted this picture online because it's my favorite ice breaker to do with teachers at conferences and workshops. However, I will use the context to illustrate how I introduced Clothesline to about 150 teachers, coaches, administrators today.

**As teachers were discussing, I went around and asked**

- two teachers for a guess that's
**too low**(3 and 5 seconds) - two teachers for a guess that's
**too high**(30 and 40 seconds) - four teachers for a guess that's
**just right**

**I used a big black marker to write the numbers on the red papers**for the first four teachers with their "wrong" answers. I then had them place the red papers on the 25 feet long clothesline hanging on the side wall.

**I had the last four teachers write their "just right" guesses on the green slips.**

**You'll notice the green slips might be hard to read from a distance.**I did this on purpose so that we could get the visual effect (from a distance) of placing their green slips accurately on the clothesline using correct spacing (sorry, no pictures), based on where the red slips were originally placed. I reminded the teachers that this is a

*dynamic*number line. You can move the numbers along the clothesline as you please. Please note that the teachers (in this case) were doing all the work, thinking, critiquing, and adjusting. In other words, students should be doing the same in my class as I help facilitate the conversations.

**Throughout the rest of the day, I worked with teachers grades 7-12**during three breakout sessions. Therefore, I made a handful of cards for each breakout session to correspond to numbers or expressions relevant to them and their content area. Here's a sample:

I love when Chris used colored papers to focus on the numbers being placed (or in question). Notice the "benchmark" numbers are on white paper.

**THE ROPE**

The clothesline is 25 feet long. I think this is plenty long. I went to Home Depot and bought a 100 ft. clothesline. I made three cuts to make four lines of 25 feet. I used a flame to burn the ends of the rope so they stay in tact.

**THE CLOTHESPINS**

I noticed Chris used these to stack equivalent values together vertically. Brilliant. See above for examples that could stack.

**THE NUMBERS (or expressions)**

NCTM suggests using 3x5 cards, but then you have to use more clothespins, making the number line more static. Chris suggested using strips of paper. Using strips of paper allows the number line to be way more dynamic, allowing the numbers to slide along the clothesline or making it easy to place the numbers or take them off without the use of clothespins.

**VARIABLES**

Many teachers loved the idea of using variable expressions. Here's how I determined

*x*for each group. I asked the three teachers in possession of the variable expressions to share how long they had been working in the district. For example, three teachers shared 12, 13, and 15 years. Therefore, 40 was the value of our variable,

*x*.

**FUTURE USE**

Whenever I give a professional development workshop for teachers from now on, I will be using Clothesline. IT'S AWESOME! It

*is*a master number sense maker. If I happen to be at your district or school doing PD, I'll bring a handful of clotheslines to raffle off (or give away). At the end of my last session today, it was awesome to have two excited calculus teachers be extremely thankful for receiving a clothesline. One walked away saying, "I'm going to use this Wednesday." Their first day of school! Calculus!

Last, but not least, test it out at home if you have the chance. My five-year-old son and I had fun this past weekend. He threw me a few surprises.

**Clothesline 1**

I just tossed up a few numbers on the clothesline for him to first get acquainted with the idea of numbers on the clothesline. "Move the pieces of paper so they make sense to you."

**Clothesline 2**

My son caught me off guard when he pursued something

*he*was interested in. 1, 2, 3, 6.

"

*What*?"

**Clothesline 3**

I wanted to see how my son did with spacing the numbers.

"Show me where four and five go."

**I'd love to hear about your Clothesline experiences.**

Check out Kristin Gray's great post from the other day. I love how much she anticipates student thinking in preparing for a successful Clothesline activity.

Clothesline,

930