# K.OA.A.2

Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem.

## Summary:

Students should be introduced to word problems that depict real-life situations where they encounter the concepts of addition and subtraction within 10. Using word problems that involve real-life situations helps young learners see the relevance of mathematics in the world around them and allows for the natural use of objects or drawings in representing the problems.

## Understanding the Standard:

• Teachers should challenge students with problems in a variety of contexts and ask them to decide which operation (if any) should be used to solve a problem. Students should make these decisions by acting out the problems or modeling them with manipulatives or drawings (and looking for the actions of combining, adding to, taking from, or taking apart).
• Provide students with a variety of activities that will give them practice in making the addition or subtraction process easier, always within a context the students can relate to.
• The use of manipulatives and pictures should be incorporated into the learning experience for greater understanding of taking apart and putting together.
• Early learners need a wide assortment of visual cues to help them make the connection between the abstract concept of addition and the concrete result. Teachers should represent a situation with an expression or equation after it has been modeled with manipulatives, a drawing, or a situation. This will help students make the connection between real-world objects an more abstract symbolic representations.
• Establish the meaning of the vocabulary, “addition” is combining or adding to and “subtraction” is removing some or taking away.

## Questions to Focus Instruction:

• Do students understand that when something is added to a set or two individual sets are combined, the total number of objects can be found using addition?
• Do students understand that when something is taken away from a whole set or the set is taken apart, the remaining number of objects can be found using subtraction?
• If more objects are added to a set, can students count on and produce the new total number of objects?
• If objects are taken away from a set, cans student see that the number of remaining objects has decreased?

## Skills

Prior to: Students can count fluently to 10 and assign a numeral to a set, showing the quantity in that set. Students have begun to make the connections between "combining" and addition and "taking away" and subtraction.