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How-To Guides

Step-by-step guides that teach you how to perform calculations manually.

313 guides
6 steps3 min

How to Calculate Reverse Percentage: Step-by-Step Guide

Calculate Reverse Percentage manually

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6 steps3 min

How to Calculate Percentage Off: Step-by-Step Guide

Calculate percentage off manually

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5 steps3 min

How to Calculate Percentage Error: Step-by-Step Guide

Calculate Percentage Error manually

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6 steps3 min

How to Calculate Discount: Step-by-Step Guide

Calculate discount manually with our easy guide

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5 steps5 min

How 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.

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4 steps6 min

How 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.

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5 steps5 min

How 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.

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5 steps3 min

How 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.

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4 steps5 min

How 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.

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4 steps4 min

How 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.

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4 steps5 min

How 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.

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5 steps4 min

How 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.

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5 steps7 min

How 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!

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6 steps6 min

How 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.

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5 steps3 min

How 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.

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5 steps7 min

How 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.

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5 steps3 min

How 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.

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5 steps5 min

How 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.

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5 steps5 min

How 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.

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5 steps5 min

How 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!

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4 steps6 min

How to Check for a Perfect Cube and Find its Cube Root: Step-by-Step Guide

Learn to manually check if a number is a perfect cube and find its cube root. Master the formula with a simple, step-by-step example.

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5 steps6 min

How to Check for a Perfect Square and Find Its Square Root: Step-by-Step Guide

Learn to manually check if a number is a perfect square and find its root using estimation and prime factorization. Understand the 'why' behind the calculation.

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6 steps6 min

How to Calculate Parabola Features: Focus, Directrix, and Latus Rectum

Learn to manually find a parabola's focus, directrix, and latus rectum from its equation. Step-by-step guide with formulas and examples.

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5 steps6 min

How to Calculate the Matrix Inverse: Step-by-Step Guide

Learn to calculate the inverse of 2x2 and 3x3 matrices by hand. Follow our step-by-step guide with formulas, examples, and common pitfalls.

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6 steps3 min

How to Calculate Hyperbola Properties: Step-by-Step Guide

Calculate hyperbola properties manually

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6 steps3 min

How to Calculate Eigenvalues of a 2×2 Matrix: Step-by-Step Guide

Calculate eigenvalues manually

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6 steps3 min

How to Work with Parametric Equations: Step-by-Step Guide

Learn parametric equations manually

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6 steps3 min

How to Perform Prime Factorisation: Step-by-Step Guide

Learn prime factorisation manually

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6 steps3 min

How to Generate Fibonacci Sequence and Calculate Golden Ratio: Step-by-Step Guide

Generate Fibonacci sequence and golden ratio manually

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6 steps3 min

How to Perform Modular Arithmetic: A Step-by-Step Guide

Learn modular arithmetic with our free guide

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