In this interactive object, students complete progressively more difficult exercises as a way to improve their ability to recognize resistor color code values.

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 interactive object, students view an animated depiction of Class 1 levers. A matching quiz completes the activity.

Learners examine the ways in which a motor starter circuit is protected by a main circuit breaker and overload heaters when there is excessive current.

Students use the pyramid method to solve percent problems. The pyramid grid provides a visual way to set up the equation.

This interactive learning object demonstrates how the moisture content is determined for a given sample of soil or aggregate.

Students read how to determine and calculate the void ratio for a given sample of soil or aggregate based on the weight-volume relationship.

Students read how to determine and calculate the degree of saturation for a given sample of soil or aggregate based on the weight-volume relationship.

Learners follow a four-step process to determine the empirical formula of a compound from the masses of its constituent elements. The molecular formula is determined in a fifth step using the molecular weight of the compound.

Credit interest and other

Matching percents

Move the snake using the arrow buttons to the correct answer.

Percent word problems