Learn how to calculate the percentage of any number. Formula: (Percentage ÷ 100) × Number. With 12 examples, common tricks and real-world applications.
Formula: Percentage of a number = (% ÷ 100) × Number. Example: 25% of 80 = (25÷100) × 80 = 0.25 × 80 = 20. Quick trick: 10% = move decimal one place left. 25% = divide by 4.
| Percentage | Trick | Example |
|---|---|---|
| 10% | Move decimal one place left | 10% of 340 = 34 |
| 20% | 10% × 2 | 20% of 340 = 68 |
| 25% | Divide by 4 | 25% of 80 = 20 |
| 50% | Divide by 2 | 50% of 340 = 170 |
| 75% | 50% + 25% | 75% of 80 = 60 |
| 1% | Move decimal two places left | 1% of 500 = 5 |
Siempre sustituye tu respuesta en el problema original para confirmar que es correcta.
Los errores ocurren cuando se trata de hacer todo mentalmente. Escribe cada paso.
Lee el problema dos veces antes de resolver. Identifica qué te dan y qué te piden.
Esta técnica aplica en exámenes de secundaria, preparatoria y universidad. Es fundamental dominarla antes de pasar a temas más avanzados.
Aim for 10-20 problems per concept, gradually increasing difficulty. Consistent daily practice (even 15 minutes) beats occasional marathon sessions.
1) Re-read the problem. 2) List all given information. 3) Identify what you need to find. 4) Choose the right formula. 5) Calculate step by step.
Writing each step helps you spot errors, earns partial credit on tests, and builds the habit of organized mathematical thinking.