# 2.MD.B.5

Use addition and subtraction within 100 to solve word problems involving lengths that are given in the same units, e.g., by using drawings (such as drawings of rulers) and equations with a symbol for the unknown number to represent the problem.

## Summary:

The study of measurement allows for opportunities to integrate a variety of mathematical processes for use in problem-solving. This standard focuses on students’ ability to apply their previous mastery of measuring objects to word problems that are representative of real-world situations. Additionally, students will apply their mastery of addition and subtraction processes to write equations using symbols for the unknown values and calculate the sum and differences represented in these equations.

## Understanding the Standard:

• Students should encounter a variety of word problems that involve measurement and require addition or subtraction to solve.
• Require students to use measuremnt tools to visulaize problems presented, as well as drawings and graphics.

## Questions to Focus Instruction:

• Are students able to decide whether to use the addition or subtraction process to solve for word problems?
• Can students identify the clue words that determine whether addition or subtraction is to be used?
• Can students display their answers in a visual representation that depicts the process used to solve?
• Can students represent the unknown quantity in an addition and subtraction problem and solve accordingly?
• Are students able to state the answer to the word problem in accordance with the stated measurement tasks embedded in the problem?

## Skills

Prior to: Students can measure the length of an object to the nearest inch.

Students will use the processes of addition and subtraction to solve word problems that reflect real-world situations involving measurement.

Moving Beyond:
Students will build upon previous knowledge to calculate the perimeter and area of objects using repeated addition and eventually the process of multiplication.