Arithmetic Operation

plus

$1 + 2$

1 + 2

Copy

We use the symbols as it is.

minus

$3 - 1$

3 - 1

Copy

We use the symbols as it is.

times

$2 \times 3$

2 \times 3

Copy

It comes from reading "2 x 3" as "2 times 3".

divide

$6 \divisionsymbol 3$

6 \div 3

Copy

\div comes from "divide". If you are using the physics extension, the div will be overwritten. So you must duplicate it before it is overwritten.

plus minus

$\pm 1$

\pm 1

Copy

\pm comes from "plus and minus".

minus plus

$\mp 1$

\mp 1

Copy

\mp comes from "minus and plus".

times dot

$a \cdot b = ab$

a \cdot b = ab

Copy

\cdot comes from "center dot".

divide fraction

$a \divisionsymbol b = \frac{a}{b}$

a \div b = \frac{a}{b}

Copy

This is the relationship between division and fractions.

column multiplication

$\begin{array}{r} 67 \\[-3pt] \underline{\times\phantom{0}63}\\[-3pt] 201 \\[-3pt] \underline{\phantom{0}402\phantom{0}} \\[-3pt] 4221 \end{array}$

\begin{array}{r}
67 \\[-3pt]
\underline{\times\phantom{0}63}\\[-3pt]
201 \\[-3pt]
\underline{\phantom{0}402\phantom{0}} \\[-3pt]
4221
\end{array}

Copy

The array environment is used to specify right-justification. If you use underline, a line will be drawn underneath the text. The phantom allocates a space for the characters you specify. -3pt is a way of writing to reduce the width of a line break a little.

column division

$\begin{array}{r} 7.6 \\[-3pt] 25\enclose{longdiv}{190\phantom{0}} \\[-3pt] \underline{175\phantom{.0}} \\[-3pt] 15\phantom{.}0 \\[-3pt] \underline{15\phantom{.}0} \\[-3pt] \phantom{000}0 \end{array}$

\begin{array}{r}
  7.6 \\[-3pt]
25\enclose{longdiv}{190\phantom{0}} \\[-3pt]
  \underline{175\phantom{.0}} \\[-3pt]
  15\phantom{.}0 \\[-3pt]
  \underline{15\phantom{.}0} \\[-3pt]
  \phantom{000}0
\end{array}

Copy

You can use \enclose{longdiv} to represent the long division. The phantom is used to substitute whitespace for the specified characters and align them.

modular equivalence

$a \equiv b \mod n$

a \equiv b \mod n

Copy

\mod and \equiv come from modular arithmetic and equivalence. Three lines are for describe equivalence.

modular equivalence with parentheses

$a \equiv b \pmod n$

a \equiv b \pmod n

Copy

\pmod means "mod with parentheses".

modular equivalence like binary operator

$\gcd(a, b) = \gcd(b, a \bmod b)$

\gcd(a, b) = \gcd(b, a \bmod b)

Copy

\bmod means "mod used like a binary operator".

proportional

$x \propto y$

x \propto y

Copy

\propto comes from "proportional to".