Better Lesson
Better Lesson: Missing Number Equations
Second graders will become more comfortable making sense of equations presented in missing answer (traditional) and missing number ( nontraditional) formats.
National Council of Teachers of Mathematics
Nctm: Figure This: Which Is Worth More, a Smile or a Frown?
Solve for the value of the smiles and frowns to find out how much a smile is worth, in this activity. A challenge that focuses on number sense, number combinations, and unknowns. Included are examples of how this skill is applied in real...