1. Old value = 5
New value = 10
Percent Change = 10 - 5 / 5 × 100%
= 5/5 × 100%
= 100% (increase)
2. Old value = 40
New value = 20
Percent Change = 20 - 40 / 40 × 100%
= -20/40 × 100%
= -1/2 × 100%
= -50% (decrease)
3. Old value = $50
New value = $40
Percent Change = $40 - $50 / $50 × 100%
= -$10/$50 × 100%
= -1/5 × 100%
= -20% (decrease)
