2.OA.A.1

Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.

Use addition and subtraction to solve two-step word problems. Here's an example problem: During a road trip, Steve ate 14 M&Ms and Carly ate 17. There are now 6 M&Ms left. How many M&Ms were in the bag before the road trip? This translates to 14 + 17 + 6. Conclude by leading this investigation. One additional puzzle can be found here.