# Launch

In the first phase, the teacher launches the Problem with the whole class. Launches include connecting to prior knowledge, as well as presenting the challenge of the Problem.

### Connecting to Prior Knowledge

First, the teacher helps position the new Problem within prior understandings and Problems. This is the time when the teacher clarifies prior definitions, reviews old concepts and connects the Problem to past experiences of the students. When planning for this part, teachers should ask themselves the following questions:

- What prior knowledge do my students need to build on?
- How can I use that information to support this Problem?

### Presenting the Challenge

After connecting the Problem to prior knowledge, the teacher then helps students understand the Problem setting, the mathematical context, and the challenge.

The following questions can help the teacher prepare for the launch:

- What are students expected to do?
- What do the students need to know to understand the context of the story and the challenge of the Problem?
- What difficulties for students can I foresee?
- How can I help without giving away too much of the Problem solution?

It is critical that the teacher leaves the potential of the task intact, while giving students a clear picture of what is expected. He or she must be careful not to tell too much and consequently lower the challenge of the task to something routine, or to be so directive that the rich array of strategies that may evolve from a more open launch of the Problem is lost.