# Length Indirect Comparer Sub Trajectory: Non-Measurement Comparison

Compares the length of two objects by representing them with a third object. Uses terms: long, longer, longest, short, shorter, shortest. When asked to measure, may assign a length by guessing or moving along a length while counting (without equal-length units). May be able to measure with a ruler, but often lacks understanding or skill (e.g., ignores starting point).

## Other Examples:

• Compares length of two objects with a piece of string.
• Moves finger along a line segment, saying, "10, 20, 30, 31, 32."
• Measures two objects with a ruler to check if they are the same length, but does not accurately set the "zero point" for one of the items.

## Help your student become a(n) Length Indirect Comparer

Activities are carefully planned to make the (easier!) direct instruction difficult or impossible, so children are challenged to use a third object (e.g., a piece of string) to compare two others (e.g., width of a heavy table and a doorway). Discussion focuses on transitive inference--if A is longer than B and B is longer than C, then A is longer than C.