## How We Got There

*the flipped-mastery model of education*. In this model, students work through course content at a flexible pace, receiving direct instruction a synchronously when they're ready for it. When they get to the end of a unit, they must demonstrate mastery of the learning objectives before they move on.

## Two Problems, Two Solutions

*always*at different places in their understanding, yet we continue to treat them as a homogeneous group. Mastery learning exposes and accepts this diversity, but logistics often prevent teachers from meeting learners' individual needs.

## How to Organize a Flipped-Mastery Model

*Learning objectives*, such as "be able to calculate using the combined gas law."*Learning objects*that we would make available for students to use, such as videos, problem sets, and references to specific sections of the textbook.*Required activities*that students had to complete to demonstrate mastery for each objective, such as hands-on experiments, inquiry-based labs, teacher-led demonstrations, and online simulations.

**FIGURE 1. Unit on Gas Laws, Broken Down by Objectives, Learning Objects, and Required Activities.**

Flipping for Mastery-table

Learning Objectives | Learning Objects | Required Activities | |
---|---|---|---|

Gases 1 | Be able to understand how gases differ from solids and liquids and how gas pressure is measured. | "Video 1 Worksheet 1 Text Section 12.1–12.2" | |

Gases 2 | Be able to conceptually and mathematically explain Boyle's, Charles's, and Gay-Lussac's laws. | "Video 2 Worksheet 2 Text Section 12.3" | "Online Simulation Boyle's Law Lab Charles's Law Lab" |

Gases 3 | Be able to calculate using the combined gas law. | "Video 3 Worksheet 3 Text Section 12.3" | Take-Home Lab |

Gases 4 | Be able to calculate using the ideal gas law. | "Video 4 Worksheet 4 Text Section 12.4" | |

Gases 5 | Be able to conceptually and mathematically explain Dalton's law of partial pressure and Graham's law of diffusion. | "Video 5 Worksheet 5 Text Section 12.5" | Graham's Law Demo |

Gases 6 | Be able to do gas-stoichiometry problems in which gases are not collected at standard temperature and pressure. | "Video 6 Worksheet 6 Text Section 12.6" | Gas-Stoichiometry Lab |

Gases 7 | Be able to determine the molar mass of a gas that is collected at nonstandard conditions. | "Video 7 Worksheet 7 Text Section: Not in Text" |

## How to Pace

## How to Assess

## Formative Checks

## Summative Retakes

*more*valuable. Their time in the class is maximized. The teacher's main role is not to be a disseminator of knowledge, but rather a facilitator of learning.