Addition and Subtraction of Length Units
Overview
Students begin this unit by measuring various objects with multiple centimeter cubes, creating a mental benchmark for the
centimeter. They apply their knowledge of using centimeter cubes to measure by moving from repeated physical units to the iteration of one physical unit. Students begin to use centimeter rulers, meter sticks, and meter tapes to measure various objects. Through the practice of measuring various items and learning mental benchmarks for measurement, students develop estimation. They also develop their skills for selecting an appropriate measuring tool. Students use different length units to measure and compare lengths. They learn that the larger the unit, the fewer number of units in a given measurement.
Students begin this unit by measuring various objects with multiple centimeter cubes, creating a mental benchmark for the
centimeter. They apply their knowledge of using centimeter cubes to measure by moving from repeated physical units to the iteration of one physical unit. Students begin to use centimeter rulers, meter sticks, and meter tapes to measure various objects. Through the practice of measuring various items and learning mental benchmarks for measurement, students develop estimation. They also develop their skills for selecting an appropriate measuring tool. Students use different length units to measure and compare lengths. They learn that the larger the unit, the fewer number of units in a given measurement.
Vocabulary

Standards covered:
2.MD.1 Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes. 2.MD.2 Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen. 2.MD.3 Estimate lengths using units of inches, feet, centimeters, and meters. 2.MD.4 Measure to determine how much longer one object is than another, expressing the length difference in terms of a standard length unit. 2.MD.5 Use addition and subtraction within 100 to solve word problems involving lengths that are given in the same units 