You searched for: “effectual
effective, effectual, efficient
effective (i FEK tiv) (adjective)
Capable of having a decisive or desired result: Brushing your teeth twice every day is an effective way to reduce tooth decay.
effectual (i FEK choo uhl) (adjective)
Referring to something which or someone who has produced or caused a desired result: A trained police force was effectual in reducing crime in the city.
efficient (i FISH uhnt) (adjective)
Achieving the desired result with a minimum of waste: The new water heater in the kitchen was very efficient because it worked fast and used much less energy.

Reading the manual on teaching fractions is a very effective way to increase the effectual nature of the teachers who are always striving to be efficient.