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CALCULATION GUIDES

Learn the method, then use the tool.

Short practical guides built around the formulas and workflows available in SolveGrid.
GUIDE

Percentage increase and decrease

Find percentage change from an original value to a new value.

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GUIDE

Profit margin vs markup

Understand cost-based markup and selling-price margin.

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GUIDE

Simple interest formula

Calculate interest from principal, annual rate, and time.

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GUIDE

Loan payment formula

Understand periodic payments, total repaid, and total interest.

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GUIDE

How to plot multiple equations

Compare functions, vertical lines, tables, roots, and intersections.

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GUIDE

TI-84 style online graphing workflows

Use independent online workflows for graphs, tables, trace values, and intersections.

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GUIDE

Calculate age from a date of birth

Find calendar age in years, months, and days on a chosen date.

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GUIDE

Gaussian elimination for linear systems

Use row operations to solve systems with several unknown values.

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GUIDE

Matrix inverse and determinant

Understand when an inverse exists and how determinants guide solutions.

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GUIDE

Matrix methods for linear systems

Compare Gaussian elimination, RREF, inverse, and Cramer’s rule for linear systems.

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GUIDE

Standard deviation formula

Choose sample or population standard deviation and interpret spread.

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GUIDE

Engineering notation and scientific notation

Read powers of ten, SI prefixes, and compact technical values clearly.

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GUIDE

Euler method for differential equations

Use a fixed step and local slope to estimate a first-order initial value problem.

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GUIDE

Runge-Kutta RK4 method

Understand four-slope RK4 updates for numerical ordinary differential equations.

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GUIDE

Symbolic algebra simplification and differentiation

Understand what a symbolic algebra engine can simplify, differentiate, and compare.

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GUIDE

Graphical method for two-variable linear programming

Build constraints, identify feasible corner points, and test an objective function.

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GUIDE

Two-node nodal analysis

Set up a conductance matrix for a two-node resistor circuit with injected currents.

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GUIDE

How to choose a statistical test

Separate descriptive statistics, t-tests, correlation, and one-way ANOVA by the question and data type.

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