Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

I wish to display to people that a number is a total. I have decided to use the greek symbol for sum:

Σ

Do I prefix or suffix numbers with this symbol?

Given the total is 10.

Σ10

or

10Σ
share|improve this question
9  
If you really want to use $\Sigma$ for this, maybe $\Sigma=10$. –  André Nicolas May 14 '12 at 23:36
2  
Indeed, a mathematician would interpret $\Sigma10$ as adding up some number of tens, and $10\Sigma$ as ten times some sum. –  Gerry Myerson May 14 '12 at 23:41
    
$\Sigma$ is generally used as an operator. Thus you might write $\sum_{i=1}^{3} a_i = 10$, which means that the sum of $a_i$ for $i$ from $1$ to $3$, i.e. $a_1 + a_2 + a_3$, is $10$. –  Robert Israel May 14 '12 at 23:52
    
THank you all. I would accept @Andre's comment if it were an answer. –  Valamas May 15 '12 at 0:04

1 Answer 1

If $S_n$ is some sequence (for $n=a, a+1, a+2, \cdots, b-1, b$), its sum (total), $T$, is: $$T=\sum_{n=a}^b S_n$$

which is simply another way of saying

$$T=S_a+S_{a+1}+\cdots + S_{b-1}+S_{b}$$


Note also that $$C \sum_{n=a}^b S_n=C(S_a+S_{a+1}+\cdots + S_{b-1}+S_{b})$$

share|improve this answer
2  
$S_n$ is a sequence; $T$ is (the value of) a series. –  Gerry Myerson May 15 '12 at 0:30

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.