Example of the Envelope and Counter Model

Two expressions joined by an equal sign form what?

Put these steps in order to write an equation from an envelope and counter model.

In the envelope and counter model, the center dividing line stands for the equal sign ($=$).

In the envelope and counter model, match each part to what it stands for in the equation.

Match each algebra term to its meaning. Use the equation $x + 3 = 8$ as a guide.

The terms on one side of an equation, such as $x + 3$, form an algebraic _____.

Write an equation: the sum of $x$ and 12 is 30.

Which equation represents an envelope worth $x$ counters plus $3$ counters equaling $8$ counters?

What do the envelope, one counter, and the center line represent?

In the model for $x+3=8$, what do the envelope, a counter, and the center line represent?