View Full Version : Help with a simple mathematics script

05-08-2009, 10:17 PM
I want to find the summation of the integers from 1-100. So i want to find 1+2+3+4+5+...n. The first thing i thought about issuing a for loop to print the number of terms, and i was then thinking of a function to sum up all of the terms.

for ($i=1; $i<100;$i++) {
print $i; // prints terms 1-100

Any recommendations to find the summation of the terms? Thanks.


05-08-2009, 10:40 PM
for ($i=1; $i<100;$i++) {
$sum = $i;

echo $sum;

I think that should do it.

Len Whistler
05-08-2009, 10:47 PM
This will output the results line by line. An echo outside the loop would be the final total.

$array = range(1,100);

foreach ($array as $value) {
$sum = $sum + $value;
echo "$sum<br>";


09-29-2009, 08:17 AM
Alternatively, you can use the arithmetic sequence equation:
(n/2)*(2a+(n-1)), where n = max number, a = min number.


$a = 1;
$n = 100;

$sum = ($n/2)*(2*($a)+($n-1));

echo sum; // echos '5050'


EDIT: woah, didn't realize this topic was old. Was using the search function. <_<