Practical calculations make tax concepts concrete. Suppose you earned $48,000 gross in the year and are eligible to claim a fictional standard deduction of $12,000 for simplicity. Taxable income equals gross income minus deductions. This is the starting number for applying tax rates or credits. Understanding this subtraction helps you see how deductions directly lower the income subject to tax, which simplifies estimating owed tax quickly for budgeting. Use the example numbers provided — no real-world thresholds are used here.