Original number increased by 50% = 2820

50% increase means the fraction becomes $\frac{3}{2}$. If $3 \text{ units} = 2820$, then $1 \text{ unit} = 940$, so $2 \text{ units} = 940 \times 2 = 1880$.

Subtracting 50% of 2820 instead of finding the base number. $2820 - 1410 = 1410$, which is incorrect because the 50% increase was on the original number, not on 2820.

In profit and loss problems, a 50% markup on cost price works identically: $\text{Selling Price} = 1.5 \times \text{Cost Price}$. Master percentage multiplier techniques to solve both percentage and profit-loss questions quickly.