Example

Solving 2x=62x = 6 Using the Envelope and Counter Model

The envelope and counter model can be used to visualize solving an equation in which the variable is multiplied by a coefficient. To model the equation 2x=62x = 6, place two identical envelopes on the left side of the workspace (each containing an unknown but equal number of counters, xx) and six counters on the right side. Because both sides must balance, the six counters need to be split into two equal groups — one group for each envelope. Dividing 6÷2=36 \div 2 = 3 shows that each group contains three counters, so each envelope holds 33. Algebraically, dividing both sides of 2x=62x = 6 by 22 yields 2x2=62\frac{2x}{2} = \frac{6}{2}, which simplifies to x=3x = 3. This result checks out because 23=62 \cdot 3 = 6. The physical process of splitting counters into equal groups mirrors the algebraic step of dividing both sides by the coefficient, illustrating why the Division Property of Equality is needed when the variable is multiplied by a number rather than added to or subtracted from one.

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Updated 2026-04-21

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