Standard: 1.OA.A1 – 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.
Grade level: Grade 1
Subject: Mathematics
Domain: Operations & Algebraic Thinking
Teacher Overview
This standard focuses on using addition and subtraction to solve word problems within 20. It is crucial as it lays the foundation for mathematical problem-solving and critical thinking skills that will be built upon in later grades. Students should be able to count to 20, recognize numbers, and understand basic addition and subtraction concepts.
After mastering this standard, students will be able to solve more complex word problems and will be prepared to understand the properties of addition and subtraction and begin exploring multiplication and division.
Common Misconception 1
A common misconception is that the order of numbers in addition or subtraction does not matter. This is incorrect because, while addition is commutative, subtraction is not.
Intervention 1
Use manipulatives like counters or blocks to show that changing the order in subtraction results in different answers, reinforcing the concept through visual and hands-on activities.
Common Misconception 2
Another misconception is that subtraction always makes numbers smaller. This is incorrect because subtracting zero does not change the number, and subtracting a negative number can increase the value.
Intervention 2
Provide examples and practice problems where students subtract zero or negative numbers to illustrate that subtraction does not always result in a smaller number.
Prerequisite Knowledge
Students should be comfortable with basic counting up to 20, recognize numbers, and understand simple addition and subtraction concepts.
Subsequent Knowledge
Students will develop skills to solve more complex word problems, understand the properties of addition and subtraction, and begin to explore multiplication and division concepts.
Instructional Activities
- Using story problems with physical objects
- Drawing pictures to represent word problems
- Creating equations with symbols for unknowns
- Role-playing shopping scenarios
- Using interactive math games and apps
