The equivalence exists because tenths represent one-tenth of a whole. Having 20 tenths means multiplying 20 by 1/10, resulting in 20/10, which simplifies to 2 wholes. Conversely, expressing 2 as 20 tenths yields the same amount.
The formula modeling this scenario is (-2)(4). The breakdown of the process shows that shifting from 0 to -2 represents -2 units, and similar deductions follow through other steps reaching -8, with a total change of -2 units per step. Thus, the model results in (-2) × 4.