The ability to quickly calculate percentages, interest, and discounts protects you from financial mistakes and helps you find genuine value in every transaction.
Bill 4,500 | 15% tip = 675 | After 10% discount: 4,500×0.9 = 4,050 + 608 tip = 4,658 total
Move decimal point one place left. 3,450 × 10% = 345.
Calculate 10%, add half of that. 10%=20, half=10, total 15%=30.
Understanding loan interest. 2% difference on 5M loan over 20 years = 1.2M difference.