Addition and subtraction of lengths represent composing and separating segments, finding total distance, or determining the difference between two measurements when lengths are expressed in the same unit. Learners interpret rulers, number lines, diagrams, and word problems to choose operations and preserve the unit, understanding that unlike units must be converted before combining; fractional, decimal, and more complex unit-conversion cases are beyond this scope.
Lengths can be added when pieces are joined and subtracted when a piece is taken away or when finding the difference. First, check that all measurements use the same unit.
Example: A strip of paper is centimeters long. A -centimeter piece is cut off, and then a -centimeter piece is attached. How long is the strip now?
The strip is centimeters long.
Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill
Earned ?