Lesson Plan: Adding and Subtracting Lengths: Numbers up to 20 Mathematics
This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to find the total length of two objects and find the difference in length between two objects by using a ruler to measure the lengths in centimeters.
Objectives
Students will be able to
- use a ruler to measure two objects in centimeters,
- use addition to find the total length of two objects in centimeters,
- use subtraction to find the difference in length between the two objects in centimeters.
Prerequisites
Students should already be familiar with
- using a ruler to measure an object in centimeters,
- recognizing that we measure from 0 cm,
- basic concepts and strategies for addition,
- basic concepts and strategies for subtraction.
Exclusions
Students will not cover
- measuring the length of more than two objects,
- values greater than 20 cm.
