Foundation
USE WHEN
Worker efficiency changes by a percentage, or workforce changes during the job.
BEST METHOD
LCM Work Method
TARGET
90–120 sec
MASTERY
not started
Worker efficiency changes by a percentage, or workforce changes during the job.
Work rate is proportional to efficiency; time is inversely proportional to efficiency for fixed work.
Use efficiency units and LCM total work.
Take total work as an LCM-based unit model and adjust rates after % changes.
Timed drill
Identify the base or invariant before you calculate.
Attempt first · Standard Example
Attempt first · CAT-Level Example
3-level practice ladder
Foundation
CAT Standard
Advanced / Hybrid
This pattern is a recurring CAT arithmetic archetype.