Represent and solve problems involving addition and subtraction
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.
Related Lessons
Lesson 207
Warm up with a Mystery Math Mistake to add 9 and 5 using a double 10-frame and a decompose strategy. Use near-doubles to add with double 10-frames and a compensation strategy.
