Lesson Plan 2 – “Filling the Pool”

Madalyn Christian

The Task

A rope ladder with 8 rungs that are 9 inches

apart is hanging over the side of a pool. The

first rung is 9 inches from the bottom of the

empty pool. If we fill the pool at a rate of 1

foot per hour, how long will it take to reach

the top rung of the ladder?

Mathematical Thinking

Actual-sized ladder

Used problem solving strategies

Breaking it down in steps

I asked:

“What did you do first?”

“What do you need to do next?”

“Why did you choose to solve it this way?”

Mathematical Thinking

Allowed students to choose own partners..

Had 3 partner groups share their work and how they solved the problem (each had a different strategy)

Strategies were: act it out, draw a picture, write an equation, make a chart

Was surprised by the work that the partner groups produced (Andrew and David)

Problem Solving Strategies

Nang’s Work- TAG

Pedagogical Knowledge

Effective moves:

Preparing steps to break down the task, but not showing the students until about half the class was ready to move on to that step/ needed it

Encouraged students to make T-charts to organize info (CT gave the idea)

Life-sized ladder made visualizing the problem easier/ could act it out

Pedagogical Knowledge

Professional Growth

How I would change the lesson:

Have more closure

Bring it back to the question to make the context more real:

Will the pool be filled up in time for the pool party?

Instead of just: “It will take 6 hours”

Allow students to make life-sized ladders on butcher paper

Professional Growth

Ask more questions to students when they shared their work

Introduce the task in a different way in order to intimidate the students less

Questions?

How else could I introduce this task? The students had no idea what to do when they first read it.

How would I make this task more “real” to the students?

I thought about extending the lesson using a “not so nice” number for inches, such as it would take 1 hour to fill 14 inches, instead of 1 foot… but what other way could I extend this lesson to make it more difficult now that the concept is grasped?