Math talks help students actively develop new ways of thinking about numbers. Math talks encourage students to use their prior knowledge about math, make meaningful connections to mathematical problems and communicate their mathematical understanding in a clear and concise way.
Math talks are extremely accessible, help develop growth mindset, and allow for the participation of learners of all ability levels. One of my favourite Number Talk websites was developed by educator and mathematician, Mary Bourassa. The number talks she, and other collaborators have developed ask students to use their knowledge of number sense to determine which of four numbers does not belong. What is amazing about this exercise is that ALL students, regardless and ability can engage in this type of rich and open discussion. Answers can be incredibly simple or more comprehensive and nuanced.
These talks are a great way of determining a students level of comfort with different curriculum strands, encourages class discussion and helps a teacher determine a students depth of mathematical understanding.