These change unknown (missing addend) story problems were created to be used for differentiating with in kindergarten, first grade, and second grade classrooms (29 pages in all). I have made 2 or 3 copies of each problem to differentiate with a similar problem. (First problem includes the equation 4+?=13 and the following worksheets 11+?=34)
These could be used as a station in a math workshop, as work for guided groups, as homework, as assessments, or they could be used in a math journal.
There are also Spanish only and bilingual versions available.
Aligned to Common Core standards:
1.OA.1- Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.
1.OA.2- Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.
1.OA.8- Determine the unknown whole number in an addition or subtraction equation relating three whole numbers.