Numbers & Their Operations

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Types of Numbers

Z
Integers ($\mathbb{Z}$)

$..., -3, -2, -1, 0, 1, 2, 3, 4, ...$

P
Prime Numbers

Integers divisible by $1$ and itself only. Smallest prime is $2$.

Q
Rational Numbers ($\mathbb{Q}$)

$\frac{\text{integer}}{\text{integer}}$ — e.g., $\frac{4}{7}, -3\frac{1}{8}, 0.3, 2.\dot{6}\dot{5}, 92, \sqrt{16}$

I
Irrational Numbers

Cannot be expressed as fractions — e.g., $\pi, \sqrt{2}, e$

R
Real Numbers ($\mathbb{R}$)

All rational and irrational numbers combined.

Standard Form

$A \times 10^n$

where $n$ is an integer, and $1 \leq A < 10$

SI Prefixes

Prefix Symbol Value
tera T $10^{12}$
giga G $10^{9}$
mega M $10^{6}$
kilo k $10^{3}$
— base unit —
milli m $10^{-3}$
micro μ $10^{-6}$
nano n $10^{-9}$
pico p $10^{-12}$

Laws of Indices

Multiplication
$a^m \times a^n = a^{m+n}$
Division
$a^m \div a^n = a^{m-n}$
Power of Power
$(a^m)^n = a^{mn}$
Product Power
$(ab)^m = a^m b^m$
Quotient Power
$\left(\frac{a}{b}\right)^n = \frac{a^n}{b^n}$
Negative Index
$a^{-n} = \frac{1}{a^n}$
Zero Index
$a^0 = 1$
Fractional Index
$a^\frac{1}{n} = \sqrt[n]{a}$
General Fractional
$a^\frac{m}{n} = (\sqrt[n]{a})^m$