Curated OER
Using Doubles
Bring this easy shortcut to your first grade addition lesson! By adding doubles (6+6, for example), and then adding or subtracting 1, kids learn how to solve simple addition problems with ease. This trick is especially helpful for...
Pennsylvania Department of Education
Comparing Sets
Young scholars count back with cubes to model subtraction problems. In this subtraction lesson plan, students compare sets of problems and record their results in a table.