Solving Unknowns with Addition and Subtraction Fact Families

The video tutorial explains how to solve for unknown amounts using addition and subtraction fact families. It begins with a marshmallow problem and introduces the concept of fact families, showing how to write related equations. The tutorial covers solving for unknown addends and sums, highlights common mistakes, and applies these concepts to solve the initial problem. The lesson concludes with a summary of the key points.

How many marshmallows were in the bag to begin with?

Explain how to find the unknown addend in the equation 9 plus blank equals 22.

What common mistake might someone make when solving for an unknown in a subtraction problem?

What is the equation that represents the relationship between the number of marshmallows eaten and the number left?

How can you represent the fact family for the numbers 26 and 7?