How do you write mathematical symbols?

Question

I have noticed that some people in their questions or answers use the correct symbols for sigma, infinity, partial differential etc. How do you do these with an ordinary keyboard? Please forgive an oldie for asking if the answer is obvious.

Answer 1

You can bookmark this page and copy the symbols here: ± √ π × θ ÿ ¢ ° ¹ ² ³ ¼ ½ ¾ ‼ ⅓ ⅔ ⅛ ⅜ ⅝ ⅞ ∏ ∑ ∫ ≈ ≠ ≡ ≤ ≥

You can also turn the number lock on and press Alt + .

Answer 2

You can find most of these symbols by using a mathematical keyboard, which can be downloaded online.

Answer 3

∑

I go to MS word and select insert symbol. It's a pain though and most of the time you'd be better off just typing "(sigma)" instead

Answer 4

Type mathematical symbols Shortcut Keys

Please Press alt key and given number

+ Alt + 43 plus sign
- Alt + 45 minus sign
± Alt + 241 plus minus sign
× Alt + 0215 multiplication sign
÷ Alt + 0247 division sign
= Alt + 61 equal sign
% Alt + 37 percent sign
‰ Alt + 0137 permille percent sign / per thousand sign
. Alt + 46 single angle mark opening quote
/ Alt + 47 fraction separator
¼ Alt + 0188 quarter
½ Alt + 0189 half
¾ Alt + 0190 three quarters
( Alt + 40 open round bracket
) Alt + 41 close round bracket
[ Alt + 91 open square bracket
] Alt + 93 close square bracket
{ Alt + 123 open brace, curly bracket
} Alt + 125 close brace, curly bracket
< Alt + 60 less than
> Alt + 62 greater than
≥ Alt + 242 greater than or equal
≤ Alt + 243 less than or equal
√ Alt + 251 square root symbol
ⁿ Alt + 252 to the power n
¹ Alt + 0185 to the power 1
² Alt + 0178 to the power 2 / to the second power / squared
³ Alt + 0179 to the power 3 / to the third power / cubed
π Alt + 227 pi symbol
Σ Alt + 228 sum
µ Alt + 230 Greek letter mu
∞ Alt + 236 Read the entire article about the infinity symbol here
∩ Alt + 239 intersection
≡ Alt + 240 equivalent to, identical
⌠ Alt + 244 curl up integral sign
⌡ Alt + 245 curl down integral sign
≈ Alt + 247 approximately equal, similar
° Alt + 248 More Alt Codes for the degree symbol

Answer 5

if you're using windows, do this:
start
programs
accessories
system tools
character map

just select and copy symbols that you wanna paste :)