Summing numbers 0 to 100

**Jassim** · March 22nd 2009, 12:38 PM

Suppose you have a list of numbers from zero to one hundred. How quickly can you add them all up without using a calculator?

**running-gag** · March 22nd 2009, 01:00 PM

You can use Gauss method
$S=1 + 2 + 3 + \cdots + 98 + 99 + 100$
$S=100 + 99 + 98 + \cdots + 3 + 2 + 1$

$2S=101 + 101 + 101 + \cdots + 101 + 101 + 101$

2S is the sum of 100 terms equal to 101

Therefore $S=\frac{100\cdot101}{2}=5050$

**Jassim** · March 22nd 2009, 01:41 PM

thanks very much for your help

**stapel** · March 23rd 2009, 05:21 AM

Thread: Summing numbers 0 to 100

LinkBack

Thread Tools

Display

Summing numbers 0 to 100

thx

Similar Math Help Forum Discussions

[SOLVED] Combinatorics question involving summing digits of numbers

What is the symbol for summing odd numbers?

Summing proof

Induction with summing

Summing - question

Search Tags