Number talks were developed for classroom teachers to engage students in "mental math" through grappling with interesting mathematics problems. Educators can use number talks regularly as introductions to the day’s mathematical practice, as “warm ups” for other lessons, or as stand-alone extended engagements with mathematical concepts
This set utilizes a number bond to help students decompose the second addend in order to make a friendly or landmark number. The cards are scaffolded and gradually take away the support. The final two sets are number sentences to allow students to pick different landmark or friendly numbers. They key is mental math here.