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Arithmetic Formulas & Calculators

Understand arithmetic formulas with explanations, examples and interactive tools.

Arithmetic

Addition

\(a+b\)

Combine two quantities.

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Arithmetic

Subtraction

\(a-b\)

Find the difference between two quantities.

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Arithmetic

Multiplication

\(a\times b\)

Repeated addition of equal groups.

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Arithmetic

Division

\(a\div b\)

Share a quantity into equal groups; divisor must not be zero.

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Arithmetic

Place Value

\(d\times 10^n\)

Value of a digit depends on its position.

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Arithmetic

Money Conversion

\(\text{paise}=100\times\text{rupees}\)

One rupee equals one hundred paise.

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Arithmetic

Total Cost

\(\text{price}\times\text{quantity}\)

Multiply price per item by number of items.

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Arithmetic

Remainder Relation

\(a=bq+r\)

Dividend equals divisor times quotient plus remainder; 0 ≤ r < |b|.

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Arithmetic

Even Number

\(n=2k\)

An integer is even when divisible by 2.

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Arithmetic

Odd Number

\(n=2k+1\)

An integer is odd when it is one more than an even integer.

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Arithmetic

Fraction of a Quantity

\(\frac{a}{b}\times N\)

Find a fractional part of a whole number.

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Arithmetic

Fraction Addition

\(\frac ab+\frac cd=\frac{ad+bc}{bd}\)

Add two fractions using a common denominator.

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Arithmetic

Fraction Multiplication

\(\frac ab\times\frac cd=\frac{ac}{bd}\)

Multiply the numerators and denominators.

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Arithmetic

Average (Mean)

\(\bar x=\frac{\sum x_i}{n}\)

Add values and divide by number of values.

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Arithmetic

Percentage

\(p=\frac{\text{part}}{\text{whole}}\times100\)

Express part of a whole out of one hundred.

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Arithmetic

Percent of a Number

\(x\times\frac{p}{100}\)

Calculate a given percentage of a number.

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Arithmetic

Ratio Simplification

\(a:b=\frac{a}{g}:\frac{b}{g}\)

Divide both terms by their greatest common divisor.

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Arithmetic

HCF of Two Integers

\(\operatorname{HCF}(a,b)\)

Greatest positive integer dividing both integers.

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Arithmetic

LCM of Two Integers

\(\operatorname{LCM}(a,b)=\frac{|ab|}{\operatorname{HCF}(a,b)}\)

Smallest nonnegative common multiple; both nonzero for positive LCM.

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Arithmetic

Simple Interest

\(SI=\frac{PRT}{100}\)

Interest on principal P at annual rate R% for T years.

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Arithmetic

Profit

\(\text{Profit}=SP-CP\)

Selling price minus cost price.

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Arithmetic

Profit Percentage

\(\frac{SP-CP}{CP}\times100\)

Profit relative to cost price; CP must be positive.

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Arithmetic

Discount

\(D=\frac{MP\times d}{100}\)

Discount on marked price at rate d%.

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Arithmetic

Speed

\(v=\frac{d}{t}\)

Speed equals distance divided by elapsed time.

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Arithmetic

Distance

\(d=vt\)

Distance at constant speed.

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Arithmetic

Time

\(t=\frac{d}{v}\)

Travel time at constant nonzero speed.

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Arithmetic

Compound Amount

\(A=P(1+\frac{r}{100})^t\)

Amount with annual compounding.

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