Lesson objective: Solve word problems using addition strategies.
This lesson provides an opportunity for students to apply their knowledge and understanding of using a number line and related addition and subtraction facts to a reallife situation. Students are asked to figure out whether the money Kareem has saved is enough money to buy a baseball and a glove.
Key Concept students will use:

We can use strategies such as making ten, counting on, and the relationship between addition and subtraction to add and subtract within 20.
Skills students will use:
 Representing and solving an addition/subtraction word problem within 10 (Unit K10; K.OA.A.2).
 Understanding that the meaning of addition and/or subtraction doesn’t change when different strategies are used (Unit K10).
Students engage in Mathematical Practice 7 (Look for and make use of structure) as they solve a word problem using the relationship between additon and subtraction using number lines and/or a triangle diagram.
Key vocabulary:
 equation
 number line
 related facts