How-To Guides
Step-by-step guides that teach you how to perform calculations manually.
How to Calculate Percentile Rank: Step-by-Step Guide
Learn to calculate percentile rank by hand! This guide explains the formula, provides a worked example, and covers common pitfalls. Understand where your data stands.
Read guideHow to Calculate Quartiles and IQR: Step-by-Step Guide
Learn to calculate quartiles (Q1, Q2, Q3) and the Interquartile Range (IQR) by hand with a simple, step-by-step guide and example.
Read guideHow to Calculate the Average (Arithmetic Mean): Step-by-Step Guide
Learn to calculate the arithmetic mean (average) step-by-step by hand. Includes formula, worked example, common pitfalls, and when to use a calculator.
Read guideHow to Calculate Your Test Grade: Step-by-Step Guide
Learn to manually calculate your test grade percentage and letter grade. Understand the formula, follow a worked example, and avoid common mistakes.
Read guideHow to Calculate a Confidence Interval: Step-by-Step Guide
Learn to calculate confidence intervals manually
Read guideHow to Calculate Standard Deviation: Step-by-Step Guide
Learn to calculate variance and standard deviation manually
Read guideHow to Calculate Mean, Median, and Mode: Step-by-Step Guide
Learn to calculate mean, median, and mode manually
Read guideHow to Calculate Statistics: Step-by-Step Guide
Learn statistics manually
Read guideTax and Tip Combined Calculator: Step-by-Step Guide
Calculate tax and tip combined quickly and accurately
Read guideHow to Calculate Selling Price with a Mark-Up Calculator: Step-by-Step Guide
Calculate selling price manually
Read guideHow to Calculate Reverse Percentage: Step-by-Step Guide
Calculate Reverse Percentage manually
Read guideHow to Calculate Percentage Off: Step-by-Step Guide
Calculate percentage off manually
Read guideHow to Calculate Percentage Error: Step-by-Step Guide
Calculate Percentage Error manually
Read guideHow to Calculate Discount: Step-by-Step Guide
Calculate discount manually with our easy guide
Read guideHow to Calculate a Tip: Step-by-Step Guide
Learn to manually calculate restaurant tips! This guide covers the formula, worked examples, common pitfalls, and when to use a calculator.
Read guideHow to Convert Decimals to Percentages: Step-by-Step Guide
Learn to convert any decimal to a percentage by hand! Multiply by 100 and add the percent sign. Includes formula, examples, and common pitfalls.
Read guideHow to Convert Percentages to Decimals: Step-by-Step Guide
Learn to easily convert percentages to decimals by dividing by 100. Follow our step-by-step guide with examples, common pitfalls, and fraction form.
Read guideHow to Calculate Percentage Decrease: Step-by-Step Guide
Learn to calculate percentage decrease by hand! Understand the formula, follow a worked example, and avoid common pitfalls with this easy guide.
Read guideHow to Calculate Percentage Increase: Step-by-Step Guide
Learn to calculate percentage increase between two values by hand. Understand the formula, follow a worked example, and avoid common mistakes. Free guide.
Read guideHow to Calculate Percent: Step-by-Step Guide
Learn to calculate percentages manually, understand the formula (Part/Whole * 100), and avoid common mistakes with a clear, step-by-step guide.
Read guideHow to Calculate Function Composition (f∘g)(x): Step-by-Step Guide
Learn to calculate function composition (f∘g)(x) manually with a simple formula, worked examples, common pitfalls, and when to use a calculator.
Read guideHow to Calculate Polynomial Long Division: Step-by-Step Guide
Master polynomial long division with this step-by-step guide. Learn the formula, see a worked example, avoid common pitfalls, and understand when to use a calculator.
Read guideHow to Apply Descartes' Rule of Signs: Step-by-Step Guide
Learn to use Descartes' Rule of Signs to predict the number of positive and negative real roots of a polynomial. Easy manual steps & examples!
Read guideHow to Calculate Possible Rational Roots Using the Rational Root Theorem: Step-by-Step Guide
Learn to manually list all possible rational roots of a polynomial using the Rational Root Theorem. Step-by-step guide with examples and common pitfalls.
Read guideHow to Perform Synthetic Division: Step-by-Step Guide
Master synthetic division by hand! Learn to divide polynomials by linear factors with clear steps, a worked example, and common pitfalls.
Read guideHow to Calculate the Discriminant: Step-by-Step Guide
Learn to calculate the discriminant (Δ = b²−4ac) of a quadratic equation by hand. Understand its formula, interpret roots, and avoid common pitfalls.
Read guideHow to Solve Quadratic Equations by Completing the Square: Step-by-Step Guide
Learn to solve quadratic equations by completing the square! Transform standard form to vertex form step-by-step with a worked example.
Read guideHow to Calculate Digital Root: Step-by-Step Guide
Learn to calculate the digital root of any integer by hand! Follow our easy steps, formula, and examples to master this fascinating number concept.
Read guideHow to Calculate the Sum of Digits: Step-by-Step Guide
Learn to manually calculate the sum of digits for any integer. Discover the formula, digital root, and divisibility checks with our easy-to-follow guide.
Read guideHow to Check Divisibility Rules Manually: A Step-by-Step Guide
Learn to manually check divisibility for numbers using simple rules for 2, 3, 4, 5, 6, 9, and 10. Master number sense!
Read guide