Illustrative Mathematics
Triangular Tables
Somewhat of a puzzle, this problem gets pre-algebra preteens to write an expression representing a seating chart using triangle-shaped tables. This single task is an applicable lesson for meeting sixth grade Common Core math standards....
Oregon Department of Education
Building Number Sense
It's never too early to begin a child's math education. This collection of fun hands-on activities engage youngsters in building their number sense as they learn how to count objects, identify numerals, compare amounts, and much more.