Information about Interleaved and Retrieval Practice can be found at https://www.retrievalpractice.org/.
Some free professional readings and resources that can be found at this site are linked below:
The Benefits of Interleaved Practice, Dr. Doug Rohrer (YouTube video)
The HRCE Mathematics Team in collaboration with classroom teachers have created grids of questions to support retrieval practice. It is the hope that classroom teachers will use this math routine once or twice each week to both improve mental math skills, support classroom discussion and make learning durable and long lasting.
Mathematics 7 Retrieval Practice Grids
Mathematics 8 Retrieval Practice Grids
Mathematics 9 Retrieval Practice Grids