Learners read the definitions of the prepositions "in," "on," and "at" and view examples of how these words are used. They then complete an exercise by inserting the prepositions into sentences.
In this interactive object, learners change the amount of money received from tax revenue and the amount spent on federal programs as they calculate how fiscal policy affects the gross domestic product (GDP), unemployment, inflation, the annual deficit, the national debt, and interest on the national debt.
Solving Systems of Linear Equations Using the Substitution Method
In a series of practice problems, learners use the substitution method to solve systems of linear equations, also called "simultaneous linear equations."
In this animated object, learners examine the operation of a feed-forward control system and its advantages over a closed-loop system. A brief quiz completes the activity.
In this animated object, learners examine the ratio control method used in automation when two or more ingredients are mixed. A brief quiz completes the activity.